code: func (r *ControllerExpectations) GetExpectations(controllerKey string) (*ControlleeExpectations, bool, error) {
  	exp, exists, err := r.GetByKey(controllerKey)
  	if err == nil && exists {
  		return exp.(*ControlleeExpectations), true, nil
  	}
  	return nil, false, err
  }
docs: // GetExpectations returns the ControlleeExpectations of the given controller.