All datasources done. Now to wire them up in the components.

Plus ElementRefs are now optional as they cannot be initialized

overlord/src/app/profit-loss/profit-loss.component.ts

@@ -14,8 +14,8 @@ import { ProfitLossDataSource } from './profit-loss-datasource';
   styleUrls: ['./profit-loss.component.css'],
 })
 export class ProfitLossComponent implements OnInit {
-  @ViewChild(MatPaginator, { static: true }) paginator: MatPaginator;
-  @ViewChild(MatSort, { static: true }) sort: MatSort;
+  @ViewChild(MatPaginator, { static: true }) paginator?: MatPaginator;
+  @ViewChild(MatSort, { static: true }) sort?: MatSort;
   dataSource: ProfitLossDataSource;
   form: FormGroup;
   info: ProfitLoss;