'Returns the X-[Account|Container]-Meta-Temp-URL-Key[-2] header values
for the account or container, or an empty list if none are set.
Returns 0-4 elements depending on how many keys are set in the
account\'s or container\'s metadata.
Also validate that the request
path indicates a valid container; if not, no keys will be returned.
:param env: The WSGI environment for the request.
:returns: list of tempurl keys'

def _get_keys(self, env):

    parts = env['PATH_INFO'].split('/', 4)
    if ((len(parts) < 4) or parts[0] or (parts[1] != 'v1') or (not parts[2]) or (not parts[3])):
        return []
    account_info = get_account_info(env, self.app, swift_source='FP')
    account_keys = get_tempurl_keys_from_metadata(account_info['meta'])
    container_info = get_container_info(env, self.app, swift_source='FP')
    container_keys = get_tempurl_keys_from_metadata(container_info.get('meta', []))
    return (account_keys + container_keys)
