code: func RegisterGlobalCallbackIn(ctx context.Context, f Callback, metrics ...types.Metric) {
  	if len(metrics) == 0 {
  		panic("RegisterGlobalCallback called without any metrics")
  	}
  
  	GetState(ctx).RegisterGlobalCallbacks(GlobalCallback{f, metrics})
  }
docs: // RegisterGlobalCallbackIn is like RegisterGlobalCallback but registers in a
  // given context.