def _update_known_atts(self, **kwargs):
        """Updates instance attributes with supplied keyword arguments.
        """
        for k, v in kwargs.items():
            if k not in ATTR_KEYS:
                # Warn if passed in unknown kwargs
                raise SyntaxWarning('Unknown argument: {}'.format(k))
            elif not v: # Delete attributes with falsey values
                delattr(self, k)
            else:
                setattr(self, k, v)
Updates instance attributes with supplied keyword arguments.