code: private byte[] appendArrays(byte[] first, byte[] second) {
          byte[] result = new byte[first.length + second.length];
          System.arraycopy(first, 0, result, 0, first.length);
          System.arraycopy(second, 0, result, first.length, second.length);
  
          return result;
      }
docs: Stitches the two arrays together and returns a new one.
  
  @param first Start of the new array.
  @param second End of the new array.
  @return New array based on first and second.