public static void w(Object source, String format, Object... args) {
    log(source, Log.WARN, format, args);
  }
public static void w ( Object source , String format , Object ... args ) { log ( source , Log . WARN , format , args ) ; }
Logs a string to the console using the source object's name as the log tag at the warning
level. If the source object is null, the default tag (see {@link LogUtils#TAG}) is used.

@param source The object that generated the log event.
@param format A format string, see {@link String#format(String, Object...)}.
@param args String formatter arguments.