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

    parser = tool.get_parser(u'')
    _normfile = parser.normalize_diff_filename
    def _make_detail_key(filediff):
        return (_normfile(filediff.source_file), _normfile(filediff.dest_file), filediff.is_new, filediff.deleted)
    detail_interdiff_map = {}
    simple_interdiff_map = {}
    remaining_interfilediffs = set()
    for interfilediff in interfilediffs:
        source_file = _normfile(interfilediff.source_file)
        detail_key = _make_detail_key(interfilediff)
        remaining_interfilediffs.add(interfilediff)
        detail_interdiff_map[detail_key] = interfilediff
        simple_interdiff_map.setdefault(source_file, set()).add(interfilediff)
    remaining_filediffs = []
    for filediff in filediffs:
        source_file = _normfile(filediff.source_file)
        try:
            interfilediff = detail_interdiff_map.pop(_make_detail_key(filediff))
        except KeyError:
            remaining_filediffs.append(filediff)
            continue
        (yield (filediff, interfilediff))
        if interfilediff:
            remaining_interfilediffs.discard(interfilediff)
            try:
                simple_interdiff_map.get(source_file, []).remove(interfilediff)
            except ValueError:
                pass
    new_remaining_filediffs = []
    for filediff in remaining_filediffs:
        source_file = _normfile(filediff.source_file)
        found_interfilediffs = [temp_interfilediff for temp_interfilediff in simple_interdiff_map.get(source_file, []) if ((temp_interfilediff.dest_file == filediff.dest_file) and (filediff.source_file != filediff.dest_file))]
        if found_interfilediffs:
            remaining_interfilediffs.difference_update(found_interfilediffs)
            for interfilediff in found_interfilediffs:
                simple_interdiff_map[source_file].remove(interfilediff)
                (yield (filediff, interfilediff))
        else:
            new_remaining_filediffs.append(filediff)
    remaining_filediffs = new_remaining_filediffs
    new_remaining_filediffs = []
  ...

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

def get_matched_interdiff_files(tool, filediffs, interfilediffs):