Black explodes list unnecessarily with long variable name

[hauntsaninja]

Black explodes the list in the following:

def foo():
    assert long_long_long_long_var == [
        0, 1, 2, 3, 4, 10, 11, 12, 13, 14, 15, 16, 17, 18
    ]

If you rename the variable to something short, Black no longer explodes the list.