class_docstr: GraphConverter
  
  Convert a graph with the modifiers by traversing from output variables.
class_docstr_tok: ["GraphConverter","Convert","a","graph","with","the","modifiers","by","traversing","from","output","variables","."]
code: def _prepare_modifiers(self, modifiers=[]):
      mfs = []
      for modifier in modifiers:
          if isinstance(modifier, (list)):
              mfs += self._prepare_modifiers(modifier)
          else:
              mfs += [modifier]
      return mfs
  
imports: from collections import defaultdict
  import nnabla
  import nnabla.functions
label_desc: Use image node_id 2 for calling the GraphConverter obj's underlying member method code with example usage: obj._prepare_modifiers(modifiers) and returns: mfs