code: protected static final String printable(String s) {
  		if (s == null)
  			return "null";
  		StringBuffer retval = new StringBuffer(s.length() + 16);
  		retval.append("'");
  		@SuppressWarnings("unused")
  		char ch;
  		for (int i = 0; i < s.length(); i++) {
  			addPrintable(retval, s.charAt(i));
  		}
  		retval.append("'");
  		return retval.toString();
  	}
docs: simple utility method -- good for debugging.
  
  @param s the s
  @return the string