public static void init(LogConfiguration logConfiguration, Printer... printers) {
    if (sIsInitialized) {
      Platform.get().warn("XLog is already initialized, do not initialize again");
    }
    sIsInitialized = true;

    if (logConfiguration == null) {
      throw new IllegalArgumentException("Please specify a LogConfiguration");
    }
    sLogConfiguration = logConfiguration;

    sPrinter = new PrinterSet(printers);

    sLogger = new Logger(sLogConfiguration, sPrinter);
  }
Initialize log system, should be called only once.

@param logConfiguration the log configuration
@param printers         the printers, each log would be printed by all of the printers
@since 1.3.0
xlog/src/main/java/com/elvishew/xlog/XLog.java