Indent the outer argument if it fits in one line, rather than the inner one

[anntzer]

The title may sound cryptic but this is what I mean

$ echo 'a_very_indented_function(another_very_long_function(key0=val0, key1=val1, key2=val2))' | yapf
a_very_indented_function(another_very_long_function(key0=val0,
                                                    key1=val1,
                                                    key2=val2))

I'd argue

a_very_indented_function(
    another_very_long_function(key0=val0, key1=val1, key2=val2))

is clearly better.