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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _ReadFormatDataTypeDefinition( self, definitions_registry, definition_values, definition_name, is_member=False):
 """Reads a format data type definition. Args: definitions_registry (DataTypeDefinitionsRegistry):
 data type definitions registry. definition_values (dict[str, object]):
 definition values. definition_name (str):
 name of the definition. is_member (Optional[bool]):
 True if the data type definition is a member data type definition. Returns: FormatDefinition: format definition. Raises: DefinitionReaderError: if the definitions values are missing or if the format is incorrect. """

    if is_member:
      error_message = 'data type not supported as member'
      raise errors.DefinitionReaderError(definition_name, error_message)

    definition_object = self._ReadLayoutDataTypeDefinition(
        definitions_registry, definition_values, data_types.FormatDefinition,
        definition_name, self._SUPPORTED_DEFINITION_VALUES_FORMAT)

    # TODO: disabled for now
    # layout = definition_values.get('layout', None)
    # if layout is None:
    #   error_message = 'missing layout'
    #   raise errors.DefinitionReaderError(definition_name, error_message)

    definition_object.metadata = definition_values.get('metadata', {})

    attributes = definition_values.get('attributes', None)
    if attributes:
      unsupported_attributes = set(attributes.keys()).difference(
          self._SUPPORTED_ATTRIBUTES_FORMAT)
      if unsupported_attributes:
        error_message = 'unsupported attributes: {0:s}'.format(
            ', '.join(unsupported_attributes))
        raise errors.DefinitionReaderError(definition_name, error_message)

      byte_order = attributes.get('byte_order', definitions.BYTE_ORDER_NATIVE)
      if byte_order not in definitions.BYTE_ORDERS:
        error_message = 'unsupported byte-order attribute: {0!s}'.format(
            byte_order)
        raise errors.DefinitionReaderError(definition_name, error_message)

      definition_object.byte_order = byte_order

    return definition_object