protected function _fieldsReturn($type, $context, $fields, $schema) {
		if ($type === 'create' || $type === 'update') {
			$data = $context->data();

			if (isset($data['data']) && is_array($data['data']) && count($data) === 1) {
				$data = $data['data'];
			}
			if ($fields && is_array($fields) && is_int(key($fields))) {
				$data = array_intersect_key($data, array_combine($fields, $fields));
			}
			$method = "_{$type}Fields";
			return $this->{$method}($data, $schema, $context);
		}
		return empty($fields) ? '*' : join(', ', $fields);
	}