private void DeleteOptionSets(IEnumerable <CustomisationImportRequest> requests)
        {
            var response = new CustomisationImportResponse();

            foreach (var request in requests)
            {
                var optionMetadata =
                    CustomisationImportService.ExtractOptionSetsFromExcel(request.ExcelFile.FileName,
                                                                          Controller, response);
                foreach (var metadata in optionMetadata)
                {
                    if (metadata.IsSharedOptionSet &&
                        XrmRecordService.GetSharedPicklists().Any(p => p.SchemaName == metadata.SchemaName))
                    {
                        XrmRecordService.DeleteSharedOptionSet(metadata.SchemaName);
                    }
                    Assert.IsFalse(XrmRecordService.GetSharedPicklists().Any(p => p.SchemaName == metadata.SchemaName));
                }
            }
        }