code: func (r *ControllerExpectations) LowerExpectations(controllerKey string, add, del int) {
  	if exp, exists, err := r.GetExpectations(controllerKey); err == nil && exists {
  		exp.Add(int64(-add), int64(-del))
  		// The expectations might've been modified since the update on the previous line.
  		klog.V(4).Infof("Lowered expectations %#v", exp)
  	}
  }
docs: // Decrements the expectation counts of the given controller.