模拟Golang标准库Time接口，提供Freeze,Travel等功能。
Run xtime Example:
type Clock interface {
After(d time.Duration) <-chan time.Time
Now() time.Time
Since(t time.Time) time.Duration
Until(t time.Time) time.Duration
Sleep(d time.Duration)
Tick(d time.Duration) <-chan time.Time
NewTicker(d time.Duration) *MockTicker
Timer(d time.Duration) *MockTimer
AfterFunc(d time.Duration, f func()) *MockTimer
WithDeadline(parent context.Context, d time.Time) (context.Context, context.CancelFunc)
WithTimeout(parent context.Context, t time.Duration) (context.Context, context.CancelFunc)
}
type Cop interface {
Freeze(t time.Time)
Travel(t time.Time)
Scale(scale float64)
Return()
ApplyOption(...Option) []Option
}
type Mock interface {
Clock
Cop
}