def is_valid(self):
validity = True<EOL>for element in self._validity_map:<EOL><INDENT>if self._validity_map[element] is not VALID:<EOL><INDENT>validity = False<EOL><DEDENT><DEDENT>return validity<EOL>
Tests if ths form is in a valid state for submission.

        A form is valid if all required data has been supplied compliant
        with any constraints.

        return: (boolean) - false if there is a known error in this
                form, true otherwise
        raise:  OperationFailed - attempt to perform validation failed
        compliance: mandatory - This method must be implemented.