def test_nasa_as_dict_minimal(self):
"""
Test that NASA.as_dict does not contain empty, optional attributes
"""
nasa_dict = NASA().as_dict()
keys = list(nasa_dict.keys())
self.assertNotIn('Tmin', keys)
self.assertNotIn('Tmax', keys)
self.assertNotIn('E0', keys)
self.assertNotIn('Cp0', keys)
self.assertNotIn('CpInf', keys)
self.assertNotIn('label', keys)
self.assertNotIn('comment', keys)
