'Verify append_col() ignores the header if data.headers has
not previously been set'

def test_add_column_with_header_ignored(self):

    new_col = ('reitz', 'monke')
    data.append_col(new_col, header='first_name')
    self.assertEqual(data[0], tuple([new_col[0]]))
    self.assertEqual(data.width, 1)
    self.assertEqual(data.height, len(new_col))
    self.assertEqual(data.headers, None)
