def METHOD_NAME(self):
    """Test outcome of valid and invalid *chain* arguments."""
    path = pathDatafile(self.no_pdb['file'])
    self.assertRaises(TypeError, parseMMCIF, path, chain=['SX0'])
    self.assertRaises(ValueError, parseMMCIF, path, chain='')
    self.assertIsNone(parseMMCIF(path, chain='$'))
    self.assertEqual(parseMMCIF(path, chain='SX0').numAtoms(), 
                    self.no_pdb['chain_SX0_atoms'],
                    'parseMMCIF failed to parse correct number of atoms '
                    'when chain SX0 is specified')