old_contents: # graph drawing and interface to graphviz
  from nx_pydot import *
  from nx_agraph import *
  from nx_pylab import *
  from layout import *
  
new_contents: # graph drawing and interface to graphviz
  from nx_pydot import *
  from nx_agraph import *
  from nx_pylab import *
  from layout import *
  import layout
  
subject: add import to fix test complaints