old_contents: import networkx as nx
  import os
  
  def check_for_change(input_file, anm):
       timestamp_file = os.stat(input_file).st_mtime
       timestamp_graph = anm.overlay.input._graph.graph['timestamp']
       return timestamp_file != timestamp_graph
  
  
  
new_contents: import networkx as nx
  import os
  
  def check_for_change(input_file, anm):
      print "input_file", input_file, "anm", anm
      timestamp_file = os.stat(input_file).st_mtime
      print anm['input']._graph.graph
      timestamp_graph = anm.timestamp
      return timestamp_file != timestamp_graph
  
subject: fix bug in monitoring