code: def _initialize_operation_name_to_id(self):
      
      operation_name_to_id = {}
      for i, operation in enumerate(self._operations):
        operation_name_to_id[operation.name] = i
      return operation_name_to_id
docs: Initializer for _operation_name_to_id.
  
      Returns:
        a {string: int}, mapping operation names to their index in _operations.