def __init__ ( self, default_value = NoDefaultSpecified, **metadata ):
        if default_value is not NoDefaultSpecified:
            self.default_value = default_value

        if len( metadata ) > 0:
            if len( self.metadata ) > 0:
                self._metadata = self.metadata.copy()
                self._metadata.update( metadata )
            else:
                self._metadata = metadata
            # By default, private traits are not visible.
            if (self._metadata.get('private') and
                    self._metadata.get('visible') is None):
                self._metadata['visible'] = False
        else:
            self._metadata = self.metadata.copy()

        self.init()
Post setattr the maximum datetime.
dataset/ETHPy150Open enthought/traits/traits/trait_handlers.py/TraitType.__init__--crossover with--dataset/ETHPy150Open ContinuumIO/ashiba/enaml/enaml/widgets/bounded_datetime.py/BoundedDatetime._post_setattr_maximum