    @Test
    public void givenProjektWithNoFreeSlots_whenUserIsAssigned_thenFullyBooked() {

        // Given
        Long userId = addUser(createSampleTeilnehmer());
        Projekt fullyBookedProjekt = createSampleProjektBuilder().plaetzeGesamt(5).plaetzeReserviert(5).build();
        Long projectId = addProject(fullyBookedProjekt);

        given()
            .pathParam("projectId", projectId)
            .pathParam("userId", userId)
            .contentType(ContentType.JSON)
        .when()
            .put(BASE_URL + "/projects/{projectId}/users/{userId}")
        .then()
            .statusCode(HttpStatus.SC_CONFLICT);
    }