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 _force_list(self, o):
      if isinstance(o, (tuple)):
          return list(o)
      if not isinstance(o, (list)):
          return [o]
      return o
  
imports: from collections import defaultdict
  import nnabla
  import nnabla.functions
label_desc: Use image node_id 3 for calling the GraphConverter obj's underlying member method code with example usage: obj._force_list(o) and returns: o, list, list