cities = frozenset(["Frankfurt", "Basel","Freiburg"])

cities.add("Strasbourg")
print(cities)

00bb873ba059eedfa0f102a7f9748f1f69ece4bf
<mask token>

<mask token>
cities.add('Strasbourg')
print(cities)

cities = frozenset(['Frankfurt', 'Basel', 'Freiburg'])
cities.add('Strasbourg')
print(cities)

cities = frozenset(["Frankfurt", "Basel","Freiburg"])

cities.add("Strasbourg")
print(cities)
