code: void log( @Nullable Bundle bundle, int level, String message, @Nullable Throwable exception )
      {
          logImpl( bundle, level, message, exception, m_fqcn );
      }
docs: This method is used by the FrameworkHandler to log framework events.
  
  @param bundle    The bundle that caused the event.
  @param level     The level to be logged as.
  @param message   The message.
  @param exception The exception, if any otherwise null.