code: static boolean[] compactArray(boolean[] array, int index, int length)
      {
          if (index == 0 && length == array.length) {
              return array;
          }
          return Arrays.copyOfRange(array, index, index + length);
      }
docs: Returns an array containing elements in the specified range of the specified array.
  If the range matches the entire array, the input array will be returned.
  Otherwise, a copy will be returned.