How to control the extent of the camera in 2D map?


I want to know how to avoid the black area when I move the camera and I don’t want the 2D map can be scrolled infinitely in the horizontal direction.

  In the Cesium's API, I only found two patterns of the MapMode2D, the one is INFINITE_SCROLL, the other one is ROTATE, but it is a pity that the two are not what I want.

 I hope you can help me to solve it, thanks