/**
  * Method returns either {@code String} or {@code Integer} value.
  *
  * @param left Whether return left or right value.
  * @return Either left or right value.
  */
 private static GridEither<String, Integer> getValue(boolean left) {
   return left
       ? GridEither.<String, Integer>makeLeft("left")
       : GridEither.<String, Integer>makeRight(20);
 }