def _update_required(self, settings):
'''
update required settings
@param settings: new settings
'''
if KRequired.implementedBy(settings):
self._required.update(object_walk(settings))
else:
raise TypeError('invalid required settings')
def required(self, value):
'''
set required settings separately
@param value: required settings
'''
if KRequired.implementedBy(value):
self._required.clear()
self._update_required(value)
else:
raise TypeError('invalid required settings')
