code: private static boolean needsEscaping(String name, int location) throws ArrayIndexOutOfBoundsException
     {
        if (name.charAt(location) == '_' && name.length() >= location + 6)
        {
           return name.charAt(location + 1) == 'x' && HEX_DIGITS.indexOf(name.charAt(location + 2)) != -1
              && HEX_DIGITS.indexOf(name.charAt(location + 3)) != -1
              && HEX_DIGITS.indexOf(name.charAt(location + 4)) != -1
              && HEX_DIGITS.indexOf(name.charAt(location + 5)) != -1;
        }
        else
        {
           return false;
        }
     }
docs: Returns true if <code>name.charAt(location)</code> is the underscore character and the
  following character sequence is 'xHHHH_' where H is a hex digit.
  
  @param name
  the name to check.
  @param location
  the location to look at.
  @throws ArrayIndexOutOfBoundsException
  if location > name.length()