diff --git a/python/ycm/buffer.py b/python/ycm/buffer.py
index 636506ae..91daa352 100644
--- a/python/ycm/buffer.py
+++ b/python/ycm/buffer.py
@@ -27,6 +27,10 @@ from ycm.client.event_notification import EventNotification
 from ycm.diagnostic_interface import DiagnosticInterface
 
 
+# Emulates Vim buffer
+# Used to store buffer related information like diagnostics, latest parse
+# request. Stores buffer change tick at the parse request moment, allowing
+# to effectively determine whether reparse is needed for the buffer.
 class Buffer( object ):
 
   def __init__( self, bufnr, user_options ):
diff --git a/python/ycm/tests/test_utils.py b/python/ycm/tests/test_utils.py
index 30740188..03c5c56f 100644
--- a/python/ycm/tests/test_utils.py
+++ b/python/ycm/tests/test_utils.py
@@ -253,10 +253,6 @@ class VimBuffer( object ):
     return [ ToUnicode( x ) for x in self.contents ]
 
 
-def EmulateCurrentBufferChange():
-  VIM_MOCK.current.buffer.changedtick += 1
-
-
 class VimMatch( object ):
 
   def __init__( self, group, pattern ):