public ExaminationResult FilterExamination(SearchFilter filter) { if (string.IsNullOrEmpty(_examinationType)) { throw new InvalidOperationException("The repository is not initialized"); } // get examination from {_examinationType} table return(new ExaminationResult { Content = $"{InstanceName}: FilterExamination: type = {_examinationType}, {filter.GetLog()}. Using ConnectionString = {_connectionString}" }); }