diff --git a/catalyst/examples/simple_loop.py b/catalyst/examples/simple_loop.py
index dc130b3a..46965b98 100644
--- a/catalyst/examples/simple_loop.py
+++ b/catalyst/examples/simple_loop.py
@@ -1,13 +1,13 @@
-import pandas as pd
 import talib
 
+import pandas as pd
 from catalyst import run_algorithm
 from catalyst.api import symbol
 
 
 def initialize(context):
     print('initializing')
-    context.asset = symbol('xrp_btc')
+    context.asset = symbol('btc_usd')
 
 
 def handle_data(context, data):
@@ -27,25 +27,25 @@ def handle_data(context, data):
     pass
 
 
-# run_algorithm(
-#     capital_base=250,
-#     start=pd.to_datetime('2015-08-01', utc=True),
-#     end=pd.to_datetime('2017-9-30', utc=True),
-#     data_frequency='daily',
-#     initialize=initialize,
-#     handle_data=handle_data,
-#     analyze=None,
-#     exchange_name='poloniex',
-#     algo_namespace='simple_loop',
-#     base_currency='eth'
-# )
 run_algorithm(
+    capital_base=250,
+    start=pd.to_datetime('2017-08-01', utc=True),
+    end=pd.to_datetime('2017-9-30', utc=True),
+    data_frequency='daily',
     initialize=initialize,
     handle_data=handle_data,
     analyze=None,
     exchange_name='bitfinex',
-    live=True,
     algo_namespace='simple_loop',
-    base_currency='eth',
-    live_graph=False
+    base_currency='btc'
 )
+# run_algorithm(
+#     initialize=initialize,
+#     handle_data=handle_data,
+#     analyze=None,
+#     exchange_name='bitfinex',
+#     live=True,
+#     algo_namespace='simple_loop',
+#     base_currency='eth',
+#     live_graph=False
+# )
diff --git a/catalyst/exchange/bittrex/bittrex.py b/catalyst/exchange/bittrex/bittrex.py
index 6df3638e..1bca9422 100644
--- a/catalyst/exchange/bittrex/bittrex.py
+++ b/catalyst/exchange/bittrex/bittrex.py
@@ -24,7 +24,7 @@ URL2 = 'https://bittrex.com/Api/v2.0'
 
 class Bittrex(Exchange):
     def __init__(self, key, secret, base_currency, portfolio=None):
-        self.api = Bittrex_api(key=key, secret=secret.encode('UTF-8'))
+        self.api = Bittrex_api(key=key, secret=secret)
         self.name = 'bittrex'
         self.color = 'blue'
         self.base_currency = base_currency
@@ -65,10 +65,10 @@ class Bittrex(Exchange):
         return exchange_symbol.lower()
 
     def get_balances(self):
+        balances = self.api.getbalances()
         try:
             log.debug('retrieving wallet balances')
             self.ask_request()
-            balances = self.api.getbalances()
 
         except Exception as e:
             raise ExchangeRequestError(error=e)
@@ -208,7 +208,7 @@ class Bittrex(Exchange):
             )
 
     def get_candles(self, data_frequency, assets, bar_count=None,
-                    start_date=None):
+                    start_dt=None, end_dt=None):
         """
         Supported Intervals
         -------------------
diff --git a/catalyst/exchange/bittrex/bittrex_api.py b/catalyst/exchange/bittrex/bittrex_api.py
index cda7581e..38e2a444 100644
--- a/catalyst/exchange/bittrex/bittrex_api.py
+++ b/catalyst/exchange/bittrex/bittrex_api.py
@@ -39,7 +39,10 @@ class Bittrex_api(object):
         if method not in self.public:
             url += '&apikey=' + self.key
             url += '&nonce=' + str(int(time.time()))
-            signature = hmac.new(self.secret, url, hashlib.sha512).hexdigest()
+
+            signature = hmac.new(self.secret.encode('utf-8'),
+                                 url.encode('utf-8'),
+                                 hashlib.sha512).hexdigest()
             headers = {'apisign': signature}
         else:
             headers = {}
diff --git a/catalyst/exchange/bundle_utils.py b/catalyst/exchange/bundle_utils.py
index fe622b52..8f07565b 100644
--- a/catalyst/exchange/bundle_utils.py
+++ b/catalyst/exchange/bundle_utils.py
@@ -134,7 +134,7 @@ def get_adj_dates(start, end, assets, data_frequency):
     if end is None or start >= end:
         raise NoDataAvailableOnExchange(
             exchange=asset.exchange.title(),
-            symbol=[asset.symbol.encode('utf-8')],
+            symbol=[asset.symbol],
             data_frequency=data_frequency,
         )
 
@@ -243,12 +243,12 @@ def find_most_recent_time(bundle_name):
     for folder in bundle_folders:
         date = from_bundle_ingest_dirname(folder)
         if not most_recent_bundle or date > \
-                most_recent_bundle[most_recent_bundle.keys()[0]]:
+                most_recent_bundle[list(most_recent_bundle.keys())[0]]:
             most_recent_bundle = dict()
             most_recent_bundle[folder] = date
 
     if most_recent_bundle:
-        return most_recent_bundle.keys()[0]
+        return list(most_recent_bundle.keys())[0]
     else:
         return None
 
diff --git a/catalyst/exchange/data_portal_exchange.py b/catalyst/exchange/data_portal_exchange.py
index ce454303..3eebf3aa 100644
--- a/catalyst/exchange/data_portal_exchange.py
+++ b/catalyst/exchange/data_portal_exchange.py
@@ -80,7 +80,7 @@ class DataPortalExchangeBase(DataPortal):
                 return pd.concat(df_list)
 
             else:
-                exchange = self.exchanges[exchange_assets.keys()[0]]
+                exchange = self.exchanges[list(exchange_assets.keys())[0]]
                 return self.get_exchange_history_window(
                     exchange,
                     assets,
@@ -165,8 +165,8 @@ class DataPortalExchangeBase(DataPortal):
 
                     exchange_assets[asset.exchange].append(asset)
 
-                if len(exchange_assets.keys()) == 1:
-                    exchange = self.exchanges[exchange_assets.keys()[0]]
+                if len(list(exchange_assets.keys())) == 1:
+                    exchange = self.exchanges[list(exchange_assets.keys())[0]]
                     return self.get_exchange_spot_value(
                         exchange, assets, field, dt, data_frequency)
 
diff --git a/catalyst/exchange/exchange.py b/catalyst/exchange/exchange.py
index 25a11594..bb4018d5 100644
--- a/catalyst/exchange/exchange.py
+++ b/catalyst/exchange/exchange.py
@@ -87,7 +87,7 @@ class Exchange:
             self.request_cpt[now] = 0
             return True
 
-        cpt_date = self.request_cpt.keys()[0]
+        cpt_date = list(self.request_cpt.keys())[0]
         cpt = self.request_cpt[cpt_date]
 
         if now > cpt_date + timedelta(minutes=1):
@@ -167,8 +167,10 @@ class Exchange:
                 asset = self.assets[key]
 
         if not asset:
-            supported_symbols = [pair.symbol.encode('utf-8') for pair in
-                                 self.assets.values()]
+            supported_symbols = [
+                pair.symbol for pair in list(self.assets.values())
+            ]
+
             raise SymbolNotFoundOnExchange(
                 symbol=symbol,
                 exchange=self.name.title(),
@@ -552,7 +554,7 @@ class Exchange:
             portfolio.starting_cash = portfolio.cash
 
         if portfolio.positions:
-            assets = portfolio.positions.keys()
+            assets = list(portfolio.positions.keys())
             tickers = self.tickers(assets)
 
             portfolio.positions_value = 0.0
diff --git a/catalyst/exchange/exchange_algorithm.py b/catalyst/exchange/exchange_algorithm.py
index 22c26ef2..a96f893c 100644
--- a/catalyst/exchange/exchange_algorithm.py
+++ b/catalyst/exchange/exchange_algorithm.py
@@ -113,7 +113,7 @@ class ExchangeTradingAlgorithmBase(TradingAlgorithm):
             else self.sim_params.end_session
 
         if exchange_name is None:
-            exchange = self.exchanges.values()[0]
+            exchange = list(self.exchanges.values())[0]
         else:
             exchange = self.exchanges[exchange_name]
 
@@ -524,7 +524,7 @@ class ExchangeTradingAlgorithmLive(ExchangeTradingAlgorithmBase):
             self.add_pnl_stats(minute_stats)
             if self.recorded_vars:
                 self.add_custom_signals_stats(minute_stats)
-                recorded_cols = self.recorded_vars.keys()
+                recorded_cols = list(self.recorded_vars.keys())
             else:
                 recorded_cols = None
 
diff --git a/catalyst/exchange/exchange_bundle.py b/catalyst/exchange/exchange_bundle.py
index 64084316..81d9833d 100644
--- a/catalyst/exchange/exchange_bundle.py
+++ b/catalyst/exchange/exchange_bundle.py
@@ -353,7 +353,7 @@ class ExchangeBundle:
                         period_start, period_end = get_month_start_end(dt)
                         asset_start_month, _ = get_month_start_end(asset_start)
 
-                        if asset_start_month > period_start:
+                        if asset.start_date > period_start:
                             dt += timedelta(days=1)
                             continue
 
@@ -371,7 +371,7 @@ class ExchangeBundle:
                         period_start, period_end = get_year_start_end(dt)
                         asset_start_year, _ = get_year_start_end(asset_start)
 
-                        if asset_start_year > period_start:
+                        if asset.start_date > period_start:
                             dt += timedelta(days=1)
                             continue
 
diff --git a/catalyst/exchange/exchange_errors.py b/catalyst/exchange/exchange_errors.py
index c5baadec..6cd55014 100644
--- a/catalyst/exchange/exchange_errors.py
+++ b/catalyst/exchange/exchange_errors.py
@@ -6,12 +6,12 @@ from catalyst.errors import ZiplineError
 
 def silent_except_hook(exctype, excvalue, exctraceback):
     if exctype in [PricingDataBeforeTradingError, PricingDataNotLoadedError,
-                   SymbolNotFoundOnExchange, NoDataAvailableOnExchange, 
-                   ExchangeAuthEmpty ]:
+                   SymbolNotFoundOnExchange, NoDataAvailableOnExchange,
+                   ExchangeAuthEmpty]:
         fn = traceback.extract_tb(exctraceback)[-1][0]
         ln = traceback.extract_tb(exctraceback)[-1][1]
-        print "Error traceback: {1} (line {2})\n" \
-              "{0.__name__}:  {3}".format(exctype, fn, ln, excvalue)
+        print("Error traceback: {1} (line {2})\n"
+              "{0.__name__}:  {3}".format(exctype, fn, ln, excvalue))
     else:
         sys.__excepthook__(exctype, excvalue, exctraceback)
 
@@ -214,7 +214,9 @@ class PricingDataNotLoadedError(ZiplineError):
 class ApiCandlesError(ZiplineError):
     msg = ('Unable to fetch candles from the remote API: {error}.').strip()
 
+
 class NoDataAvailableOnExchange(ZiplineError):
-    msg = ('Requested data for trading pair {symbol} is not available on exchange {exchange} '
-           'in `{data_frequency}` frequency at this time. '
-           'Check `http://enigma.co/catalyst/status` for market coverage.').strip()
+    msg = (
+        'Requested data for trading pair {symbol} is not available on exchange {exchange} '
+        'in `{data_frequency}` frequency at this time. '
+        'Check `http://enigma.co/catalyst/status` for market coverage.').strip()
diff --git a/catalyst/exchange/exchange_utils.py b/catalyst/exchange/exchange_utils.py
index b9e6cf21..f12f4df1 100644
--- a/catalyst/exchange/exchange_utils.py
+++ b/catalyst/exchange/exchange_utils.py
@@ -42,7 +42,9 @@ def get_exchange_symbols(exchange_name, environ=None):
     filename = get_exchange_symbols_filename(exchange_name)
 
     if not os.path.isfile(filename) or \
-            pd.Timedelta(pd.Timestamp('now', tz='UTC') - last_modified_time(filename)).days > 1:
+                    pd.Timedelta(pd.Timestamp('now',
+                                              tz='UTC') - last_modified_time(
+                        filename)).days > 1:
         download_exchange_symbols(exchange_name, environ)
 
     if os.path.isfile(filename):
@@ -67,9 +69,11 @@ def get_exchange_auth(exchange_name, environ=None):
     else:
         data = dict(name=exchange_name, key='', secret='')
         with open(filename, 'w') as f:
-            json.dump(data, f, sort_keys=False, indent=2, separators=(',', ':'))
+            json.dump(data, f, sort_keys=False, indent=2,
+                      separators=(',', ':'))
             return data
 
+
 def get_algo_folder(algo_name, environ=None):
     if not environ:
         environ = os.environ
@@ -163,6 +167,7 @@ def get_exchange_minute_writer_root(exchange_name, environ=None):
 
     return minute_data_folder
 
+
 def get_exchange_bundles_folder(exchange_name, environ=None):
     exchange_folder = get_exchange_folder(exchange_name, environ)
 
diff --git a/catalyst/exchange/poloniex/poloniex.py b/catalyst/exchange/poloniex/poloniex.py
index 43954036..76d51332 100644
--- a/catalyst/exchange/poloniex/poloniex.py
+++ b/catalyst/exchange/poloniex/poloniex.py
@@ -33,7 +33,7 @@ log = Logger('Poloniex', level=LOG_LEVEL)
 
 class Poloniex(Exchange):
     def __init__(self, key, secret, base_currency, portfolio=None):
-        self.api = Poloniex_api(key=key, secret=secret.encode('UTF-8'))
+        self.api = Poloniex_api(key=key, secret=secret)
         self.name = 'poloniex'
         self.assets = {}
         self.load_assets()
@@ -119,9 +119,9 @@ class Poloniex(Exchange):
         return order, executed_price
 
     def get_balances(self):
-        log.debug('retrieving wallets balances')
+        balances = self.api.returnbalances()
         try:
-            balances = self.api.returnbalances()
+            log.debug('retrieving wallets balances')
         except Exception as e:
             log.debug(e)
             raise ExchangeRequestError(error=e)
diff --git a/catalyst/exchange/poloniex/poloniex_api.py b/catalyst/exchange/poloniex/poloniex_api.py
index 599a0b65..158b5fa2 100644
--- a/catalyst/exchange/poloniex/poloniex_api.py
+++ b/catalyst/exchange/poloniex/poloniex_api.py
@@ -19,19 +19,25 @@ class Poloniex_api(object):
         self.max_requests_per_second = 6
         self.request_cpt = dict()
 
-        self.public  = ['returnTicker', 'return24Volume', 'returnOrderBook',
-                        'returnTradeHistory', 'returnChartData',
-                        'returnCurrencies', 'returnLoanOrders']
-        self.trading = ['returnBalances','returnCompleteBalances','returnDepositAddresses',
-                        'generateNewAddress','returnDepositsWithdrawals','returnOpenOrders',
-                        'returnTradeHistory','returnOrderTrades',
+        self.public = ['returnTicker', 'return24Volume', 'returnOrderBook',
+                       'returnTradeHistory', 'returnChartData',
+                       'returnCurrencies', 'returnLoanOrders']
+        self.trading = ['returnBalances', 'returnCompleteBalances',
+                        'returnDepositAddresses',
+                        'generateNewAddress', 'returnDepositsWithdrawals',
+                        'returnOpenOrders',
+                        'returnTradeHistory', 'returnOrderTrades',
                         'buy', 'sell', 'cancelOrder', 'moveOrder',
-                        'withdraw', 'returnFeeInfo','returnAvailableAccountBalances',
+                        'withdraw', 'returnFeeInfo',
+                        'returnAvailableAccountBalances',
                         'returnTradableBalances', 'transferBalance',
-                        'returnMarginAccountSummary','marginBuy','marginSell',
-                        'getMarginPosition', 'closeMarginPosition','createLoanOffer',
-                        'cancelLoanOffer','returnOpenLoanOffers','returnActiveLoans',
-                        'returnLendingHistory','toggleAutoRenew']
+                        'returnMarginAccountSummary', 'marginBuy',
+                        'marginSell',
+                        'getMarginPosition', 'closeMarginPosition',
+                        'createLoanOffer',
+                        'cancelLoanOffer', 'returnOpenLoanOffers',
+                        'returnActiveLoans',
+                        'returnLendingHistory', 'toggleAutoRenew']
 
     def ask_request(self):
         """
@@ -50,7 +56,7 @@ class Poloniex_api(object):
             self.request_cpt[now] = 0
             return True
 
-        cpt_date = self.request_cpt.keys()[0]
+        cpt_date = list(self.request_cpt.keys())[0]
         cpt = self.request_cpt[cpt_date]
 
         if now > cpt_date + 1:
@@ -59,9 +65,8 @@ class Poloniex_api(object):
             return True
 
         if cpt >= self.max_requests_per_second:
-            
-            log.debug('max requests 6 reached, sleeping for 1 seconds')
-            sleep(1)
+
+            time.sleep(1)
 
             now = time.time()
             self.request_cpt = dict()
@@ -73,18 +78,23 @@ class Poloniex_api(object):
     def query(self, method, req={}):
 
         if method in self.public:
-            url = 'https://poloniex.com/public?command=' + method + '&' + urllib.parse.urlencode(req)
+            url = 'https://poloniex.com/public?command=' + method + '&' + \
+                  urllib.parse.urlencode(req)
             headers = {}
             post_data = None
         elif method in self.trading:
             url = 'https://poloniex.com/tradingApi'
             req['command'] = method
-            req['nonce']   = int(time.time()*1000)
-            post_data      = urllib.parse.urlencode(req)
-            signature      = hmac.new(self.secret, post_data, hashlib.sha512).hexdigest()
-            headers        = { 'Sign': signature, 'Key': self.key}
+            req['nonce'] = int(time.time() * 1000)
+            post_data = urllib.parse.urlencode(req)
+
+            signature = hmac.new(self.secret.encode('utf-8'),
+                                 post_data.encode('utf-8'),
+                                 hashlib.sha512).hexdigest()
+            headers = {'Sign': signature, 'Key': self.key}
         else:
-            raise ValueError('Method "' + method + '" not found in neither the Public API or Trading API endpoints')
+            raise ValueError(
+                'Method "' + method + '" not found in neither the Public API or Trading API endpoints')
 
         self.ask_request()
         req = urllib.request.Request(url, data=post_data, headers=headers)
@@ -100,15 +110,17 @@ class Poloniex_api(object):
         return self.query('returnOrderBook', {'currencyPair': market})
 
     def returntradehistory(self, market, start=None, end=None):
-        if(start is not None and end is not None):
-            return self.query('returntradehistory', 
-                              {'currencyPair': market, 'start': start, 'end': end })
+        if (start is not None and end is not None):
+            return self.query('returntradehistory',
+                              {'currencyPair': market, 'start': start,
+                               'end': end})
         else:
-            return self.query('returntradehistory', {'currencyPair': market })
+            return self.query('returntradehistory', {'currencyPair': market})
 
     def returnchartdata(self, market, period, start, end=9999999999):
-        return self.query('returnChartData', {'currencyPair': market, 'period': period,
-                          'start': start, 'end': end})
+        return self.query('returnChartData',
+                          {'currencyPair': market, 'period': period,
+                           'start': start, 'end': end})
 
     def returncurrencies(self):
         return self.query('returnCurrencies', {})
@@ -120,7 +132,7 @@ class Poloniex_api(object):
         return self.query('returnBalances')
 
     def returncompletebalances(self, account):
-        if(account):
+        if (account):
             return self.query('returnCompleteBalances', {'account': account})
         else:
             return self.query('returnCompleteBalances')
@@ -132,43 +144,54 @@ class Poloniex_api(object):
         return self.query('generateNewAddress', {'currency': currency})
 
     def returnDepositsWithdrawals(self, start, end):
-        return self.query('returnDepositsWithdrawals', {'start': start, 'end': end})
+        return self.query('returnDepositsWithdrawals',
+                          {'start': start, 'end': end})
 
     def returnopenorders(self, market):
         return self.query('returnOpenOrders', {'currencyPair': market})
 
     def returntradehistory(self, market):
-        #TODO: optional start and/or end and limit
+        # TODO: optional start and/or end and limit
         return self.query('returnTradeHistory', {'currencyPair': market})
 
     def returnordertrades(self, ordernumber):
         return self.query('returnOrderTrades', {'orderNumber': ordernumber})
 
-    def buy(self, market, amount, rate, fillorkill=0, immediateorcancel=0, postonly=0):
-        if(fillorkill):
-            return self.query('buy', {'currencyPair': market, 'rate':rate, 'amount': amount,
+    def buy(self, market, amount, rate, fillorkill=0, immediateorcancel=0,
+            postonly=0):
+        if (fillorkill):
+            return self.query('buy', {'currencyPair': market, 'rate': rate,
+                                      'amount': amount,
                                       'fillOrKill': fillorkill, })
-        elif(immediateorcancel):
-            return self.query('buy', {'currencyPair': market, 'rate':rate, 'amount': amount,
+        elif (immediateorcancel):
+            return self.query('buy', {'currencyPair': market, 'rate': rate,
+                                      'amount': amount,
                                       'immediateOrCancel': immediateorcancel, })
-        elif(postonly):
-            return self.query('buy', {'currencyPair': market, 'rate':rate, 'amount': amount,
+        elif (postonly):
+            return self.query('buy', {'currencyPair': market, 'rate': rate,
+                                      'amount': amount,
                                       'postOnly': postonly, })
         else:
-            return self.query('buy', {'currencyPair': market, 'rate':rate, 'amount': amount, })
+            return self.query('buy', {'currencyPair': market, 'rate': rate,
+                                      'amount': amount, })
 
-    def sell(self, market, amount, rate, fillorkill=0, immediateorcancel=0, postonly=0):
-        if(fillorkill):
-            return self.query('sell', {'currencyPair': market, 'rate':rate, 'amount': amount,
-                                      'fillOrKill': fillorkill, })
-        elif(immediateorcancel):
-            return self.query('sell', {'currencyPair': market, 'rate':rate, 'amount': amount,
-                                      'immediateOrCancel': immediateorcancel, })
-        elif(postonly):
-            return self.query('sell', {'currencyPair': market, 'rate':rate, 'amount': amount,
-                                      'postOnly': postonly, })
+    def sell(self, market, amount, rate, fillorkill=0, immediateorcancel=0,
+             postonly=0):
+        if (fillorkill):
+            return self.query('sell', {'currencyPair': market, 'rate': rate,
+                                       'amount': amount,
+                                       'fillOrKill': fillorkill, })
+        elif (immediateorcancel):
+            return self.query('sell', {'currencyPair': market, 'rate': rate,
+                                       'amount': amount,
+                                       'immediateOrCancel': immediateorcancel, })
+        elif (postonly):
+            return self.query('sell', {'currencyPair': market, 'rate': rate,
+                                       'amount': amount,
+                                       'postOnly': postonly, })
         else:
-            return self.query('sell', {'currencyPair': market, 'rate':rate, 'amount': amount, })
+            return self.query('sell', {'currencyPair': market, 'rate': rate,
+                                       'amount': amount, })
 
     def cancelorder(self, ordernumber):
         return self.query('cancelOrder', {'orderNumber': ordernumber})
@@ -180,4 +203,3 @@ class Poloniex_api(object):
 
     def returnfeeinfo(self):
         return self.query('returnFeeInfo')
-
diff --git a/tests/exchange/test_clock.py b/tests/exchange/test_clock.py
deleted file mode 100644
index ff74986b..00000000
--- a/tests/exchange/test_clock.py
+++ /dev/null
@@ -1,50 +0,0 @@
-from unittest import TestCase
-from logbook import Logger
-from mock import patch, sentinel
-from catalyst.exchange.simple_clock import SimpleClock
-from catalyst.utils.calendars.trading_calendar import days_at_time
-from datetime import time
-from collections import defaultdict
-from catalyst.utils.calendars import get_calendar
-import pandas as pd
-
-log = Logger('ExchangeClockTestCase')
-
-
-class ExchangeClockTestCase(TestCase):
-    @classmethod
-    def setUpClass(cls):
-        cls.open_calendar = get_calendar("OPEN")
-
-        cls.sessions = pd.Timestamp.utcnow()
-
-    def setUp(self):
-        self.internal_clock = None
-        self.events = defaultdict(list)
-
-    def advance_clock(self, x):
-        """Mock function for sleep. Advances the internal clock by 1 min"""
-        # The internal clock advance time must be 1 minute to match
-        # MinutesSimulationClock's update frequency
-        self.internal_clock += pd.Timedelta('1 min')
-
-    def get_clock(self, arg, *args, **kwargs):
-        """Mock function for pandas.to_datetime which is used to query the
-        current time in RealtimeClock"""
-        assert arg == "now"
-        return self.internal_clock
-
-    def test_clock(self):
-        with patch('catalyst.exchange.simple_clock.pd.to_datetime') as to_dt, \
-                patch('catalyst.exchange.simple_clock.sleep') as sleep:
-            clock = SimpleClock(sessions=self.sessions)
-            to_dt.side_effect = self.get_clock
-            sleep.side_effect = self.advance_clock
-            start_time = pd.Timestamp.utcnow()
-            self.internal_clock = start_time
-
-            events = list(clock)
-
-            # Event 0 is SESSION_START which always happens at 00:00.
-            ts, event_type = events[1]
-        pass