added null filter

src/app/prediction/prediction.component.spec.ts

@@ -6,6 +6,7 @@ import {RbUiComponentsModule} from '@inst-iot/bosch-angular-ui-components';
 import {FormsModule} from '@angular/forms';
 import {ValidationService} from '../services/validation.service';
 import {DataService} from '../services/data.service';
+import {ChartsModule} from 'ng2-charts';
 
 // TODO
 
@@ -21,6 +22,8 @@ describe('PredictionComponent', () => {
     TestBed.configureTestingModule({
       declarations: [ PredictionComponent ],
       imports: [
+        RbUiComponentsModule,
+        ChartsModule
       ],
       providers: [
         {provide: ApiService, useValue: apiSpy}