code: function (array, items) {
          
          if (   arguments.length !== 2
              || !(array instanceof Array)
              || !(items instanceof Array) )
              throw "IllegalArgumentException: expected two Array arguments.";
          
          // Faster than "pushing" each item individually.
          array.push.apply(array, items);
          
          return Arrays;
      }
docs: This function behaves similar to the native Array.push() method,
  except that it expects all elements to be added to be grouped
  in one Array object - as returned by Array.splice() or Array.slice().
  
  Note: this function modifies <code>array</code>.
  
  @param array {Array}
  @param items {Array}
  @returns {Arrays} To enable call-chaining.