assertFalse(options.all().isPresent(), "--all should not be present by default");
        assertFalse(options.infer().isPresent(), "--infer should not be present by default");
        assertFalse(options.model().isPresent(), "--fix-model should not be present by default");
        assertFalse(options.model().isPresent(), "--model should not be present by default");

        // But the goal should be present

            assertTrue(result.success(), "Result should be successful when no errors");
            assertEquals(2, result.processedCount(), "Should have 2 processed POMs");
            assertEquals(1, result.modifiedCount(), "Should have 1 modified POM");
            assertEquals(1, result.unmodifiedCount(), "Should have 1 unmodified POM");
            assertEquals(0, result.errorCount(), "Should have no errors");
        }

        @Test

If you check the previous app, in the UI you can see that, up to now, it lets the client decide the `id` of the `Hero` to create. 😱

We shouldn't let that happen, they could overwrite an `id` we already have assigned in the DB. Deciding the `id` should be done by the **backend** or the **database**, **not by the client**.

	accessKey := globalActiveCred.AccessKey

	testCases := []struct {
		form     http.Header
		expected APIErrorCode
	}{
		// (0) It should fail if 'X-Amz-Credential' is missing.
		{
			form:     http.Header{},
			expected: ErrCredMalformed,
		},
		// (1) It should fail if the access key is incorrect.
		{
			form: http.Header{

        assertTrue(nameIndex > 0, "Should contain name element");
        assertTrue(descriptionIndex > 0, "Should contain description element");
        assertTrue(propertiesIndex > 0, "Should contain properties element");

        // According to ELEMENT_ORDER: name should come before description, and properties should come much later
        assertTrue(nameIndex < descriptionIndex, "name should come before description");

        assertTrue(resource.getIncludes().contains("*.xml"), "Should contain *.xml");
        assertTrue(resource.getIncludes().contains("*.properties"), "Should contain *.properties");

        // Verify persistence
        Resource resourceAfter = project.getResources().get(0);
        assertEquals(2, resourceAfter.getIncludes().size(), "Should still have two includes");

        getMethodName() + "(firstElement) should return 0", 0, find(getOrderedElements().get(0)));
  }

  public void testFind_no() {
    assertEquals(getMethodName() + "(notPresent) should return -1", -1, find(e3()));
  }

  @CollectionFeature.Require(ALLOWS_NULL_VALUES)
  public void testFind_nullNotContainedButSupported() {
    assertEquals(getMethodName() + "(nullNotPresent) should return -1", -1, find(null));
  }

    assertTrue("contains(present) should return true", collection.contains(e0()));
  }

  public void testContains_no() {
    assertFalse("contains(notPresent) should return false", collection.contains(e3()));
  }

  @CollectionFeature.Require(ALLOWS_NULL_QUERIES)
  public void testContains_nullNotContainedButQueriesSupported() {
    assertFalse("contains(null) should return false", collection.contains(null));
  }

In this case, you could want to document how that external API *should* look like. What *path operation* it should have, what body it should expect, what response it should return, etc.

## An app with callbacks { #an-app-with-callbacks }

Let's see all this with an example.

Imagine you develop an app that allows creating invoices.

    /**
     * Gets the external profiles that should be considered for model building.
     *
     * @return The external profiles that should be considered for model building, never {@code null}.
     */
    List<Profile> getProfiles();

    /**
     * Sets the external profiles that should be considered for model building.
     *
     * @param profiles The external profiles that should be considered for model building, may be {@code null}.