def _validate_empty_attributes(self, attributes):
attrs_to_check = set(self._required) & set(attributes)<EOL>for attr in attrs_to_check:<EOL><INDENT>value = getattr(self, attr)  <EOL>if value is None or value == "<STR_LIT>":<EOL><INDENT>raise ValueError(<EOL>"<STR_LIT>" % attr<EOL>)<EOL><DEDENT><DEDENT>
Check that required attributes are not empty.