From 15a0b056815c2cb9b36e89d25a2bf5ab4602839a Mon Sep 17 00:00:00 2001
From: Scott Sanderson <ssanderson@quantopian.com>
Date: Wed, 7 Jun 2017 11:50:37 -0400
Subject: [PATCH] MAINT: Add validator to `validate_column`.

Who validates the validators?
---
 zipline/pipeline/pipeline.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/zipline/pipeline/pipeline.py b/zipline/pipeline/pipeline.py
index 78ee5ed5..e7c6b4de 100644
--- a/zipline/pipeline/pipeline.py
+++ b/zipline/pipeline/pipeline.py
@@ -229,6 +229,7 @@ class Pipeline(object):
             raise AssertionError("Unknown graph format %r." % format)
 
     @staticmethod
+    @expect_types(term=Term, column_name=str)
     def validate_column(column_name, term):
         if term.ndim == 1:
             raise UnsupportedPipelineOutput(column_name=column_name, term=term)