Listing directories is not a handled use case

The REST APIs allow to list Directories using the following URL:
http://localhost:8080/nuxeo/api/v1/directory/

Using the Java client, this is not possible:

Directory directory = nuxeoClient.getDirectoryManager().fetchDirectory("");
for (DirectoryEntry entry : directory.getDirectoryEntries()) {
  System.out.println("object -> " + entry.getDirectoryName());
  System.out.println("name -> " + entry.getProperties());
}

This returns the correct number of objects but null names and properties because the returned objects are not DirectoryEntries, there are Directories.

A workaround is to manually parse the JSON response but this could be cleaner by handling the use case inside the Java Client.