docs: function () {
              var values = this.__opts.values, ret = [];
              if (isArray(values)) {
                  ret.push(values.length === 0 ? " DEFAULT VALUES" : " VALUES " + this.literal(values));
              } else if (isInstanceOf(values, Dataset)) {
                  ret.push(" " + this._subselectSql(values));
              } else if (isInstanceOf(values, LiteralString)) {
                  ret.push(" " + values.toString(this));
              } else {
                  throw new QueryError("Unsupported INSERT values type, should be an array or dataset");
              }
              return ret.join("");
          }