diff --git a/mozilla_voice_tts/tts/utils/generic_utils.py b/mozilla_voice_tts/tts/utils/generic_utils.py
index f0b718fa..d7dca0ac 100644
--- a/mozilla_voice_tts/tts/utils/generic_utils.py
+++ b/mozilla_voice_tts/tts/utils/generic_utils.py
@@ -102,45 +102,6 @@ def setup_model(num_chars, num_speakers, c, speaker_embedding_dim=None):
     return model
 
 
-class KeepAverage():
-    def __init__(self):
-        self.avg_values = {}
-        self.iters = {}
-
-    def __getitem__(self, key):
-        return self.avg_values[key]
-
-    def items(self):
-        return self.avg_values.items()
-
-    def add_value(self, name, init_val=0, init_iter=0):
-        self.avg_values[name] = init_val
-        self.iters[name] = init_iter
-
-    def update_value(self, name, value, weighted_avg=False):
-        if name not in self.avg_values:
-            # add value if not exist before
-            self.add_value(name, init_val=value)
-        else:
-            # else update existing value
-            if weighted_avg:
-                self.avg_values[name] = 0.99 * self.avg_values[name] + 0.01 * value
-                self.iters[name] += 1
-            else:
-                self.avg_values[name] = self.avg_values[name] * \
-                    self.iters[name] + value
-                self.iters[name] += 1
-                self.avg_values[name] /= self.iters[name]
-
-    def add_values(self, name_dict):
-        for key, value in name_dict.items():
-            self.add_value(key, init_val=value)
-
-    def update_values(self, value_dict):
-        for key, value in value_dict.items():
-            self.update_value(key, value)
-
-
 def check_config(c):
     check_argument('model', c, enum_list=['tacotron', 'tacotron2'], restricted=True, val_type=str)
     check_argument('run_name', c, restricted=True, val_type=str)
diff --git a/mozilla_voice_tts/utils/io.py b/mozilla_voice_tts/utils/io.py
index cda974a6..434c3a03 100644
--- a/mozilla_voice_tts/utils/io.py
+++ b/mozilla_voice_tts/utils/io.py
@@ -1,16 +1,25 @@
 import re
 import json
+from shutil import copyfile
 
 class AttrDict(dict):
+    """A custom dict which converts dict keys
+    to class attributes"""
     def __init__(self, *args, **kwargs):
         super(AttrDict, self).__init__(*args, **kwargs)
         self.__dict__ = self
 
 
 def load_config(config_path):
+    """Load config files and discard comments
+
+    Args:
+        config_path (str): path to config file.
+    """
     config = AttrDict()
     with open(config_path, "r") as f:
         input_str = f.read()
+    # handle comments
     input_str = re.sub(r'\\\n', '', input_str)
     input_str = re.sub(r'//.*\n', '\n', input_str)
     data = json.loads(input_str)
@@ -19,6 +28,15 @@ def load_config(config_path):
 
 
 def copy_config_file(config_file, out_path, new_fields):
+    """Copy config.json to training folder and add
+    new fields.
+
+    Args:
+        config_file (str): path to config file.
+        out_path (str): output path to copy the file.
+        new_fields (dict): new fileds to be added or edited
+            in the config file.
+    """
     config_lines = open(config_file, "r").readlines()
     # add extra information fields
     for key, value in new_fields.items():