code: func (ctx *Context) Close() error {
  	var empty C.cudnnHandle_t
  	if ctx.internal == empty {
  		return nil
  	}
  
  	if err := result(C.cudnnDestroy(ctx.internal)); err != nil {
  		return err
  	}
  	ctx.internal = empty
  	return nil
  }
docs: //  Close destroys the underlying context.