diff --git a/plugin/vim/powerline.vim b/plugin/vim/powerline.vim
index 05cc6746..595c254e 100644
--- a/plugin/vim/powerline.vim
+++ b/plugin/vim/powerline.vim
@@ -26,10 +26,6 @@ endfunction
 
 function! s:UpdateAllWindows()
 	for winnr in range(1, winnr('$'))
-		" getwinvar() returns empty string for undefined variables. Use
-		" has_key(getwinvar(winnr, ''), 'window_id') if you care about
-		" variable being really defined (currently with w:window_id=='' it
-		" will throw E706: variable type mismatch).
 		if getwinvar(winnr, 'window_id') is# ''
 			call setwinvar(winnr, 'window_id', s:pyeval('str(uuid.uuid4())'))
 		endif
diff --git a/powerline/ext/vim/renderer.py b/powerline/ext/vim/renderer.py
index 2c7e32aa..44058379 100644
--- a/powerline/ext/vim/renderer.py
+++ b/powerline/ext/vim/renderer.py
@@ -36,8 +36,7 @@ class VimRenderer(Renderer):
 		if current:
 			mode = vim_mode()
 			contents_override = None
-			contents_cached = {segment['key']: segment['contents'] for segment in self.segments if segment['type'] == 'function'}
-			self.window_cache[window_id] = contents_cached
+			self.window_cache[window_id] = {segment['key']: segment['contents'] for segment in self.segments if segment['type'] == 'function'}
 		else:
 			mode = 'nc'
 			contents_override = self.window_cache.get(window_id)
diff --git a/powerline/renderer.py b/powerline/renderer.py
index 71da016a..1c86ade7 100644
--- a/powerline/renderer.py
+++ b/powerline/renderer.py
@@ -34,7 +34,6 @@ class Renderer(object):
 		provided they will fill the remaining space until the desired width is
 		reached.
 		'''
-
 		theme = self.get_theme()
 
 		segments = theme.get_segments(mode, contents_override)