docs: function (value) {
              var ret = false;
              var root = this.__root;
              while (root != null) {
                  var cmp = this.compare(value, root.data);
                  if (cmp) {
                      root = root[(cmp === -1) ? "left" : "right"];
                  } else {
                      ret = true;
                      root = null;
                  }
              }
              return ret;
          }