docs: function(callback, scope, args) {
          var mArgs = [null];
          if (!scope) {
            scope = this;
          }
          if (args) {
              if (!_isArr(args)) {
                args = [args];
              }
              mArgs = mArgs.concat(args);
          }
          var ord;
          while (ord !== -1 && this.hasMoreCells()){
              ord = this.nextCell();
              mArgs[0] = this.readCell();
              if (callback.apply(scope, mArgs)===false) {
                return false;
              }
          }
          this._idx = 0;
          return true;
      }