code: func (ctx *BatchedContext) SetCurrent() {
  	fn := &fnargs{
  		fn:  C.fn_setCurrent,
  		ctx: ctx.CUDAContext().ctx,
  	}
  	c := call{fn, false}
  	ctx.enqueue(c)
  }
docs: // SetCurrent sets the current context. This is usually unnecessary because SetCurrent will be called before batch processing the calls.