Wait until `node_address` becomes healthy.

    Note:
        This does not time out, use gevent.Timeout.

def wait_for_healthy(
        raiden: 'RaidenService',
        node_address: Address,
        retry_timeout: float,
) -> None:
    """Wait until `node_address` becomes healthy.

    Note:
        This does not time out, use gevent.Timeout.
    """
    network_statuses = views.get_networkstatuses(
        views.state_from_raiden(raiden),
    )

    while network_statuses.get(node_address) != NODE_NETWORK_REACHABLE:
        gevent.sleep(retry_timeout)
        network_statuses = views.get_networkstatuses(
            views.state_from_raiden(raiden),
        )