human
Complete this python program:
def _get_node(default_factory):
assistant
#Here is the Python program you requested.

    """Create a helper function for getting a node from a deployment.
    :param default_factory: A one-argument callable which is called with the
    requested UUID when no matching node is found in the deployment.
    The return value is used as the result.
    :return: A two-argument callable which accepts a ``Deployment`` or a
    ``DeploymentState`` as the first argument and a ``unicode`` string
    giving a node hostname as the second argument.  It will return a
    node from the deployment object with a matching UUID or it
    will return a value from ``default_factory`` if no matching node
    is found.
    """
    def get_node(deployment, uuid, **defaults):
        node = deployment.nodes.get(uuid)
        if (node is None):
            return default_factory(uuid=uuid, **defaults)
        return node
    return get_node