human
Here's a good function header given the following:
I wrote the below code

    def fix_deprecated(x):
        if (x in deprecated_units):
            results = [(x + u'    (deprecated)')]
            decomposed = _try_decomposed(all_units[x], format_decomposed)
            if (decomposed is not None):
                results.append(decomposed)
            return results
        return (x,)
    return did_you_mean(s, all_units, fix=fix_deprecated)

What's a good function header?
assistant
#Here's a good function header.

def did_you_mean_units(s, all_units, deprecated_units, format_decomposed):