code: def argument(
      self, name, tensor_type=None, initializer=None
  ):  # pylint: disable=missing-function-docstring
      if not name in self.arguments_index:
          argument = _Argument(name, tensor_type, initializer)
          self.arguments_index[name] = len(self.arguments)
          self.arguments.append(argument)
      index = self.arguments_index[name]
      # argument.set_initializer(initializer)
      return index
  
imports: import collections
  import enum
  import json
  import os
label_desc: Use image node_id 3 for calling the _Graph obj's underlying member method code with example usage: obj.argument(name, tensor_type, initializer) and returns: index