code: @Nonnull
    public static String getHexEncoded (@Nonnull final byte [] aInput, final int nOfs, final int nLen)
    {
      ValueEnforcer.isArrayOfsLen (aInput, nOfs, nLen);
  
      final StringBuilder aSB = new StringBuilder (nLen * 2);
      for (int i = nOfs; i < (nOfs + nLen); ++i)
      {
        final byte b = aInput[i];
        final char c1 = getHexChar ((b & 0xf0) >> 4);
        final char c2 = getHexChar (b & 0x0f);
        aSB.append (c1).append (c2);
      }
      return aSB.toString ();
    }
docs: Convert a byte array to a hexadecimal encoded string.
  
  @param aInput
  The byte array to be converted to a String. May not be
  <code>null</code>.
  @param nOfs
  Byte array offset
  @param nLen
  Number of bytes to encode
  @return The String representation of the byte array.