def test_insert_None(self):
        m = Multipeptide()
        self.assertEqual(len(m.getPrecursorGroups()), 0)

        m.insert("42_0", None)
        self.assertTrue(m.has_null_peptides())
        self.assertFalse(m.hasPrecursorGroup("42_0"))
    def test_insert_None(self):
        m = Multipeptide()
        self.assertEqual(len(m.getPrecursorGroups()), 0)

        m.insert("42_0", None)
        self.assertTrue(m.has_null_peptides())
        self.assertFalse(m.hasPrecursorGroup("42_0"))