code: public static synchronized void sdkInitialize(Context context) {
          if (sdkInitialized == true) {
            return;
          }
          BoltsMeasurementEventListener.getInstance(context.getApplicationContext());
          sdkInitialized = true;
      }
docs: Initialize SDK
  This function will be called once in the application, it is tried to be called as early as possible;
  This is the place to register broadcast listeners.