<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def distros_for_url(url, metadata=None):
 """Yield egg or source distribution objects that might be found at a URL"""

    base, fragment = egg_info_for_url(url)
    for dist in distros_for_location(url, base, metadata):
        yield dist
    if fragment:
        match = EGG_FRAGMENT.match(fragment)
        if match:
            for dist in interpret_distro_name(
                url, match.group(1), metadata, precedence=CHECKOUT_DIST
            ):
                yield dist