1package staker 2 3type Counter struct { 4 id int64 5} 6 7func NewCounter() *Counter { 8 return &Counter{id: 0} 9} 10 11func (c *Counter) Get() int64 { return c.id } 12 13func (c *Counter) Next() int64 { 14 c.id++ 15 return c.id 16}