js/libs/ember-1.5.1.js
function (index, newItems) {
    var count = get(newItems, 'length');
    if (count < 1) { return; }

    var match = this._findArrayOperation(index),
        arrayOperation = match.operation,
        arrayOperationIndex = match.index,
        arrayOperationRangeStart = match.rangeStart,
        composeIndex,
        splitIndex,
        splitItems,
        splitArrayOperation,
        newArrayOperation;

    newArrayOperation = new ArrayOperation(INSERT, count, newItems);

    if (arrayOperation) {
      if (!match.split) {
        // insert left of arrayOperation
        this._operations.splice(arrayOperationIndex, 0, newArrayOperation);
        composeIndex = arrayOperationIndex;
      } else {
        this._split(arrayOperationIndex, index - arrayOperationRangeStart, newArrayOperation);
        composeIndex = arrayOperationIndex + 1;
      }
    } else {
      // insert at end
      this._operations.push(newArrayOperation);
      composeIndex = arrayOperationIndex;
    }

    this._composeInsert(composeIndex);
  }
function (index, newItems) {
    var count = get(newItems, 'length');
    if (count < 1) { return; }

    var match = this._findArrayOperation(index),
        arrayOperation = match.operation,
        arrayOperationIndex = match.index,
        arrayOperationRangeStart = match.rangeStart,
        composeIndex,
        splitIndex,
        splitItems,
        splitArrayOperation,
        newArrayOperation;

    newArrayOperation = new ArrayOperation(INSERT, count, newItems);

    if (arrayOperation) {
      if (!match.split) {
        // insert left of arrayOperation
        this._operations.splice(arrayOperationIndex, 0, newArrayOperation);
        composeIndex = arrayOperationIndex;
      } else {
        this._split(arrayOperationIndex, index - arrayOperationRangeStart, newArrayOperation);
        composeIndex = arrayOperationIndex + 1;
      }
    } else {
      // insert at end
      this._operations.push(newArrayOperation);
      composeIndex = arrayOperationIndex;
    }

    this._composeInsert(composeIndex);
  }
Track that `newItems` were added to the tracked array at `index`.

@method addItems
@param index
@param newItems