'Tests to make sure that the \'in\' operator works.
Regression test for https://github.com/astropy/astropy/issues/3060'

def test_extname_in_hdulist(self):

    hdulist = fits.HDUList()
    hdulist.append(fits.ImageHDU(name='a'))
    assert ('a' in hdulist)
    assert ('A' in hdulist)
    assert (('a', 1) in hdulist)
    assert (('A', 1) in hdulist)
    assert ('b' not in hdulist)
    assert (('a', 2) not in hdulist)
    assert (('b', 1) not in hdulist)
    assert (('b', 2) not in hdulist)
