public void SetAssignmentsRetriever(IAssignmentsRetriever assignmentsRetriever) { if (_assignmentsRetriever != null) { _assignmentsRetriever.OnAssignmentsRetrieved -= ProcessOnAssignmentsRetrieved; } assignmentsRetriever.OnAssignmentsRetrieved += ProcessOnAssignmentsRetrieved; _assignmentsRetriever = assignmentsRetriever; }