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 patch_migrate():
    """A workaround for SQLite's inability to alter things

    SQLite abilities to alter tables are very limited (please read
    http://www.sqlite.org/lang_altertable.html for more details).
    E. g. one can't drop a column or a constraint in SQLite. The
    workaround for this is to recreate the original table omitting
    the corresponding constraint (or column).

    sqlalchemy-migrate library has recreate_table() method that
    implements this workaround, but it does it wrong:

        - information about unique constraints of a table
          is not retrieved. So if you have a table with one
          unique constraint and a migration adding another one
          you will end up with a table that has only the
          latter unique constraint, and the former will be lost

        - dropping of unique constraints is not supported at all

    The proper way to fix this is to provide a pull-request to
    sqlalchemy-migrate, but the project seems to be dead. So we
    can go on with monkey-patching of the lib at least for now.

    """

    # this patch is needed to ensure that recreate_table() doesn't drop
    # existing unique constraints of the table when creating a new one
    helper_cls = sqlite.SQLiteHelper
    helper_cls.recreate_table = _recreate_table
    helper_cls._get_unique_constraints = _get_unique_constraints

    # this patch is needed to be able to drop existing unique constraints
    constraint_cls = sqlite.SQLiteConstraintDropper
    constraint_cls.visit_migrate_unique_constraint = \
        _visit_migrate_unique_constraint
    constraint_cls.__bases__ = (ansisql.ANSIColumnDropper,
                                sqlite.SQLiteConstraintGenerator)