def METHOD_NAME(datadir):
    ds = DesignSpaceDocument()
    ds.read(datadir / "test_avar2.designspace")
    _, subDoc = next(splitInterpolable(ds))
    assert len(subDoc.axisMappings) == 1
    subDocs = list(splitVariableFonts(ds))
    assert len(subDocs) == 5
    for i, (_, subDoc) in enumerate(subDocs):
        # Only the first one should have a mapping, according to the document
        if i == 0:
            assert len(subDoc.axisMappings) == 1
        else:
            assert len(subDoc.axisMappings) == 0