code: public static void printError(Class<?> c, String msg) {
  		String preamble;
  		if(c != null)
  			preamble = "["+c.getSimpleName()+"]";
  		else
  			preamble = "";
  		
  		synchronized(System.err) {
  			System.err.println(preamble+" "+msg);
  		}
  	}
docs: print an ERROR-Level message with package name
  @param component Component from which the message originates
  @param msg ERROR-Level message