code: public static final String generateHex(final Random random, final int characters)
  	{
  		if (characters < 1)
  			throw new IllegalArgumentException("characters must be >= 1");
  
  		final char[] str = new char[characters];
  
  		for (int i = 0; i < characters; i++)
  		{
  			str[i] = hex[random.nextInt(16)];
  		}
  
  		return new String(str);
  	}
docs: Generates a hexidecimal String of length <code>characters</code>
  
  @param random
  the random number generator to use
  @param characters
  the number of characters in the resulting String
  
  @return