1.  We import the seelog in our main package  
           2.  In our main() function, we did daemon() to let the father process exit itself, and the child process be as the new process to do the works.
           3. In the new process, we use such code:
                     logger, err := log.LoggerFromConfigAsFile("seelog.xml")
                     if err != nil {
                           panic(err)
                      }
    
                        log.ReplaceLogger(logger)
                        defer log.Flush() 
          4.  In later codes in main(),  we need to use log.Errorf("....")  to do more logs        
          5.  Then we found that the log cannot be dumpped then since point 4 and then on.
          6.   Then I found that the seelog has one mechanism that it has the NewAsyncLoopLogger to do the asnLoopLogger.processQueue, which supervises the message queue's log and dump them finally.
                Then, I found the issue should be the  NewAsyncLoopLogger  should belongs to the father process ,  but in daemon  the father process should exit. 
                 So in child process the NewAsyncLoopLogger  cannot works , so it leads the later log cannot be dumped to log files.
          7.  I tried more case then: I made a new package named "test", and let the daemon function to be called in "test" package,   and let main package import "test" at the very beginning which more earlier than import "seelog",  but it still had the same issue, that the log could not be dumped (I found that the message has been sent to queue due to I add some printings and found "addMsgToQueue" had been called, but the handler of queue did not be called then) .