def _check_property(self, rest=None, require_indexed=True):
if require_indexed and not self._indexed:<EOL><INDENT>raise InvalidPropertyError('<STR_LIT>' % self._name)<EOL><DEDENT>if rest:<EOL><INDENT>raise InvalidPropertyError('<STR_LIT>'<EOL>'<STR_LIT>' %<EOL>(self._name, rest, self._name))<EOL><DEDENT>
Internal helper to check this property for specific requirements.

        Called by Model._check_properties().

        Args:
          rest: Optional subproperty to check, of the form 'name1.name2...nameN'.

        Raises:
          InvalidPropertyError if this property does not meet the given
          requirements or if a subproperty is specified.  (StructuredProperty
          overrides this method to handle subproperties.)