Misleading formatting of long parenthesized yields of tuples

[JelleZijlstra]

When code of the form (yield a, b) is split into multiple lines, Black puts the yield a and b each on its own line. This is misleading, because in fact this code yields the tuple (a, b), while Black's output makes it look like we yield only a.

Examples in the current Black style

def f():
    (
        yield abcdefg_abcdefg_abcdefg_abcdefg_abcdefg_abcdefg_abcdefg_,
        abcdefg_abcdefg_abcdefg_abcdefg_abcdefg_abcdefg_abcdefg_,
    )

Desired style

def f():
    yield (
        abcdefg_abcdefg_abcdefg_abcdefg_abcdefg_abcdefg_abcdefg_,
        abcdefg_abcdefg_abcdefg_abcdefg_abcdefg_abcdefg_abcdefg_,
    )

I encountered this in code using github.com/quora/asynq, which frequently contains statements of the form a, b = yield get_a.asynq(), get_b.asynq().