'Verify append_col() works when headers and rows exists'

def test_add_column_with_header_and_data_exists(self):

    data.headers = self.headers
    data.append(self.john)
    new_col = [10]
    data.append_col(new_col, header='age')
    self.assertEqual(data.height, 1)
    self.assertEqual(data.width, (len(self.john) + 1))
    self.assertEqual(data['age'], new_col)
    self.assertEqual(len(data.headers), (len(self.headers) + 1))
