docstr: generate random filename
docstr_tok: ["generate","random","filename"]
code: def filename(self):
      """
      generate random filename
      """
      import random
  
      return self.output_directory + str(random.random()) + ".png"
  
imports: from __future__ import division
  import numpy
  from neon import NervanaObject
label_desc: Use image node_id 3 for calling the DumpImage obj's underlying member method code with example usage: obj.filename() and returns: unknown