code: func (m *MemLogger) LogCall(lvl logging.Level, calldepth int, format string, args []interface{}) {
  	if m.lock != nil {
  		m.lock.Lock()
  		defer m.lock.Unlock()
  	}
  	if m.data == nil {
  		m.data = new([]LogEntry)
  	}
  	*m.data = append(*m.data, LogEntry{lvl, fmt.Sprintf(format, args...), m.fields, calldepth + 1})
  }
docs: // LogCall implements the logging.Logger interface.