# Norm: tuple           -- cause tuple is constant
# Mistake: set, list, dict


lst = [1, 2]
dct = {4:5, 6:7}
d = {
    #lst: (3, 4),       # mistake
    #dct: 'that',       # mistake
    0: 0,
    None: 23,
    (5, 6): [7, 8],
    23: None,
    'this': {1:2, 3:4},
    #[1, 2]: (1, 2)         # mistake
    (1, 2, 3): [1, 2],
    #{1, 2, 3}: {1, 2}      # mistake
    {1:1}: [1]

}