docs: function addDataTables(dataTables, rule) {
      if (arguments.length == 2) {
          for (var i = 0; i < dataTables.length; i++) {
              var rule;
              if (typeof arguments[1] == 'string') {
                  rule = arguments[1];
              } else if (isArray(arguments[1])) {
                  rule = arguments[1][i];
              }
              this.addDataTable(dataTables[i], rule);
          }
      } else {
          for (var i = 0; i < dataTables.length; i++) {
              var dt = dataTables[i];
              if (typeof dt == 'string') this.addDataTable(dt);else {
                  for (var key in dt) {
                      this.addDataTable(key, dt[key]);
                  }
              }
          }
      }
      return this;
  }