def _to_dict(self):
        """Return a json dictionary representing this model."""
        _dict = {}
        if hasattr(self, 'url') and self.url is not None:
            _dict['url'] = self.url
        if hasattr(self, 'gender') and self.gender is not None:
            _dict['gender'] = self.gender
        if hasattr(self, 'name') and self.name is not None:
            _dict['name'] = self.name
        if hasattr(self, 'language') and self.language is not None:
            _dict['language'] = self.language
        if hasattr(self, 'description') and self.description is not None:
            _dict['description'] = self.description
        if hasattr(self, 'customizable') and self.customizable is not None:
            _dict['customizable'] = self.customizable
        if hasattr(
                self,
                'supported_features') and self.supported_features is not None:
            _dict['supported_features'] = self.supported_features._to_dict()
        if hasattr(self, 'customization') and self.customization is not None:
            _dict['customization'] = self.customization._to_dict()
        return _dict