private void validateInput(int[] numbers) {
    if (numbers == null) {
      throw new IllegalArgumentException("You can't pass a null array as input.");
    }
  }
Tail recursive solution for this algorithm. The complexity order of this algorithm is similar
to the previous implementation, O(N) in time terms and O(1) in space terms.
src/main/java/com/github/pedrovgs/problem31/FindLongestConsecutiveSequence.java