code: public String
  printFlags() {
  	StringBuffer sb = new StringBuffer();
  
  	for (int i = 0; i < 16; i++)
  		if (validFlag(i) && getFlag(i)) {
  			sb.append(Flags.string(i));
  			sb.append(" ");
  		}
  	return sb.toString();
  }
docs: Converts the header's flags into a String