function storeUpdateFn(_doc) {
                switch (change) {
                    case 'added':
                        commit('INSERT_DOC', _doc);
                        break;
                    case 'removed':
                        commit('DELETE_DOC', id);
                        break;
                    default:
                        dispatch('deleteMissingProps', _doc);
                        commit('PATCH_DOC', _doc);
                        break;
                }
            }