commitment.go
func (c *commitment) getCommitIndex() uint64 {
	c.Lock()
	defer c.Unlock()
	return c.commitIndex
}
func (c *commitment) getCommitIndex() uint64 {
	c.Lock()
	defer c.Unlock()
	return c.commitIndex
}
func ( c * commitment ) getCommitIndex ( ) uint64 { c . Lock ( ) defer c . Unlock ( ) return c . commitIndex }
// Called by leader after commitCh is notified
Called by leader after commitCh is notified