def METHOD_NAME(self):
    assert hasattr(bio, 'vdif')
    assert 'vdif' in bio._entries
    assert 'vdif' in bio.FORMATS
    del bio.vdif
    assert 'vdif' not in bio.__dict__
    assert 'vdif' in bio.FORMATS
    assert 'vdif' in dir(bio)
    assert hasattr(bio, 'vdif')
    assert 'vdif' in bio.__dict__
    assert 'vdif' in bio.FORMATS