| playable | 此操作所用的 Playable。 |
double 当前时间（以秒为单位）。
返回 Playable 的当前本地时间。
The PlayableGraph updates the current time between Update and LateUpdate (see Execution Order),
unless SetTime is called since the last evaluation. In this case, the PlayableGraph will not automatically advance the time.
Use this templated extension method on any type that inherits from IPlayable.