public static void println(int priority, String tag, String msg, Throwable tr) {
        if (mLogNode != null) {
            mLogNode.println(priority, tag, msg, tr);
        }
    }
Instructs the LogNode to print the log data provided. Other LogNodes can
be chained to the end of the LogNode as desired.

@param priority Log level of the data being logged. Verbose, Error, etc.
@param tag Tag for for the log data. Can be used to organize log statements.
@param msg The actual message to be logged.
@param tr If an exception was thrown, this can be sent along for the logging facilities
          to extract and print useful information.
RecyclerView/Application/src/main/java/com/example/android/common/logger/Log.java