function concat(): void {
  // let array = new collections.Array(1, 2, 3, 4, 5);
  let array : collections.Array<number> = new collections.Array<number>(1, 3, 5);
  let arkTSToAppend : collections.ConcatArray<number> = new collections.Array<number>(2, 4, 6);
  let arkTSToAppend1 : collections.ConcatArray<number> = new collections.Array<number>(100, 101, 102);

  let concatArray : collections.ConcatArray<number> = array.concat(arkTSToAppend, arkTSToAppend1) as collections.ConcatArray<number>;
  console.info("concat Array length: " + concatArray.length);
  console.info("concat Array slice: " + concatArray.slice(1, 4));
  console.info("concat Array concat: " + concatArray.join());
  console.info("concat Array element: " + concatArray[1]);
}