def deploy_service_registry_and_set_urls(
    private_keys, web3, contract_manager, service_registry_address
) -> Tuple[ServiceRegistry, List[str]]:
    urls = ["http://foo", "http://boo", "http://coo"]
    c1_client = JSONRPCClient(web3, private_keys[0])
    c1_service_proxy = ServiceRegistry(
        jsonrpc_client=c1_client,
        service_registry_address=service_registry_address,
        contract_manager=contract_manager,
    )
    c2_client = JSONRPCClient(web3, private_keys[1])
    c2_service_proxy = ServiceRegistry(
        jsonrpc_client=c2_client,
        service_registry_address=service_registry_address,
        contract_manager=contract_manager,
    )
    c3_client = JSONRPCClient(web3, private_keys[2])
    c3_service_proxy = ServiceRegistry(
        jsonrpc_client=c3_client,
        service_registry_address=service_registry_address,
        contract_manager=contract_manager,
    )

    # Test that getting a random service for an empty registry returns None
    pfs_address = get_random_service(c1_service_proxy, "latest")
    assert pfs_address is None

    # Test that setting the urls works
    c1_service_proxy.set_url(urls[0])
    c2_service_proxy.set_url(urls[1])
    c3_service_proxy.set_url(urls[2])

    return c1_service_proxy, urls
def get_current_branch(cls, location):
        """
        Return the current branch, or None if HEAD isn't at a branch
        (e.g. detached HEAD).
        """
        # git-symbolic-ref exits with empty stdout if "HEAD" is a detached
        # HEAD rather than a symbolic ref.  In addition, the -q causes the
        # command to exit with status code 1 instead of 128 in this case
        # and to suppress the message to stderr.
        args = ['symbolic-ref', '-q', 'HEAD']
        output = cls.run_command(
            args,
            extra_ok_returncodes=(1, ),
            show_stdout=False,
            stdout_only=True,
            cwd=location,
        )
        ref = output.strip()

        if ref.startswith('refs/heads/'):
            return ref[len('refs/heads/'):]

        return None