{"test": "test", "test2": 15}

public getTests(): Observable<Test[]> {
    return this.http.get<Test[]>(environment.api + '/tests');   }

loadTests() {
    this.testsService.getTests().subscribe(response => {
      console.log(response);
      this.tests = response;
    });

{"changed": "test", "changed2": 15}

this.testsService.getTests().subscribe(mapToSomething)