def _GetDataTypeMap(self, name):
    """Retrieves a data type map defined by the definition file.

    The data type maps are cached for reuse.

    Args:
      name (str): name of the data type as defined by the definition file.

    Returns:
      dtfabric.DataTypeMap: data type map which contains a data type definition,
          such as a structure, that can be mapped onto binary data.
    """
    data_type_map = self._data_type_maps.get(name, None)
    if not data_type_map:
      data_type_map = self._fabric.CreateDataTypeMap(name)
      self._data_type_maps[name] = data_type_map

    return data_type_map