Integration Test with Content Fragments - How can I create a Content Fragment?

In my integration test I want to create a Content Fragment in a testfolder and then implement this Content Fragment in a testpage. (Sidenote: Manually everything I want to do in this test works.)

So far I managed to create a testpage and a testfolder, but I couldn't find a solution to create a Content Fragment. 

This code shows how I created a user (admin).

@ClassRule
public static final CQAuthorClassRule cqBaseClassRule = new CQAuthorClassRule();

@Rule
public CQRule cqBaseRule = new CQRule(cqBaseClassRule.authorRule);

static CQClient adminAuthor;

@BeforeClass
public static void beforeClass() {
    adminAuthor = cqBaseClassRule.authorRule.getAdminClient(CQClient.class);
}

and here I created a testpage and testfolder in my Test

try {
    SlingHttpResponse page = adminAuthor.createPageWithRetry(pageName, pageTitle, pageParentPath, templatePath, MINUTES.toMillis(1), 500, HttpStatus.SC_OK);

    String pagePath = page.getSlingLocation();

    LOG.info("Created page at {}", pagePath);

    // This shows that the page exists
    CQAssert.assertCQPageExistsWithTimeout(adminAuthor, pagePath, TIMEOUT, 500);


    SlingHttpResponse folder = adminAuthor.createFolder(folderName, folderTitle, folderParentPath, HttpStatus.SC_OK);

    String folderPath = folder.getSlingLocation();

    LOG.info("Created folder at {}", folderPath);

    // This shows that the folder exists
    CQAssert.assertFolderExists(adminAuthor, folderPath, folderTitle);
}

There is nothing like "createContentFragment" only "createNode"... Bu then I would have to create several Nodes and update these nodes to have the structure I want in my CRX. 
Any idea how I can create this content Fragment? Is there an API to use in integration tests?