code: func (cl *ChannelLogger) FlushLogLines() [][]interface{} {
  	logLines := make([][]interface{}, 0, cl.ch.Len())
  	cl.Flush(log.LoggerFunc(func(keyvals ...interface{}) error {
  		logLines = append(logLines, keyvals)
  		return nil
  	}))
  	return logLines
  }
docs: // Drains the next contiguous segment of loglines up to the buffer cap waiting
  // for at least one line