func (l *Log) lockAndFlushAll() {
	l.mu.Lock()
	l.flushAll()
	l.mu.Unlock()
}
func (l *Log) lockAndFlushAll() {
	l.mu.Lock()
	l.flushAll()
	l.mu.Unlock()
}
func ( l * Log ) lockAndFlushAll ( ) { l . mu . Lock ( ) l . flushAll ( ) l . mu . Unlock ( ) }
// lockAndFlushAll is like flushAll but locks l.mu first.
lockAndFlushAll is like flushAll but locks l . mu first .