def _to_dict(self):
        """Return a json dictionary representing this model."""
        _dict = {}
        if hasattr(self,
                   'customization_id') and self.customization_id is not None:
            _dict['customization_id'] = self.customization_id
        if hasattr(self, 'created') and self.created is not None:
            _dict['created'] = self.created
        if hasattr(self, 'language') and self.language is not None:
            _dict['language'] = self.language
        if hasattr(self, 'versions') and self.versions is not None:
            _dict['versions'] = self.versions
        if hasattr(self, 'owner') and self.owner is not None:
            _dict['owner'] = self.owner
        if hasattr(self, 'name') and self.name is not None:
            _dict['name'] = self.name
        if hasattr(self, 'description') and self.description is not None:
            _dict['description'] = self.description
        if hasattr(self,
                   'base_model_name') and self.base_model_name is not None:
            _dict['base_model_name'] = self.base_model_name
        if hasattr(self, 'status') and self.status is not None:
            _dict['status'] = self.status
        if hasattr(self, 'progress') and self.progress is not None:
            _dict['progress'] = self.progress
        if hasattr(self, 'warnings') and self.warnings is not None:
            _dict['warnings'] = self.warnings
        return _dict