human
I wrote the below code

    if multipart:
        return document_iters_to_multipart_byteranges(ranges_iter, boundary)
    else:
        try:
            response_body_iter = next(ranges_iter)['part_iter']
        except StopIteration:
            return ''
        def string_along(useful_iter, useless_iter_iter, logger):
            with closing_if_possible(useful_iter):
                for x in useful_iter:
                    (yield x)
            try:
                next(useless_iter_iter)
            except StopIteration:
                pass
            else:
                logger.warning(_('More    than    one    part    in    a    single-part    response?'))
        return string_along(response_body_iter, ranges_iter, logger)

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

def document_iters_to_http_response_body(ranges_iter, boundary, multipart, logger):