code: function (key) {
          assertNotNull(key);
          return binarySearch(this.slot.keys, 0, this.slot.size, key, this.slot.comparer.compare);
      }
docs: Searches for the specified key and returns the zero-based index within the entire SortedList.
  @param {Object} key The key to locate in the SortedList.
  @returns {Number}