How to use the autonetkit.ank.set_node_default function in autonetkit

r1 = g_phy.node("r1")
        r2 = g_phy.node("r2")
        r3 = g_phy.node("r3")
        r4 = g_phy.node("r4")
        r5 = g_phy.node("r5")
        r1.set("color", "blue")
        result = [(n, n.get("color")) for n in g_phy]
        expected_result  = [(r4, None), (r5, None), (r1, 'blue'), (r2, None), (r3, None)]
        self.assertListEqual(expected_result, result)
        ank_utils.set_node_default(g_phy, color="red")
        result = [(n, n.get("color")) for n in g_phy]
        expected_result = [(r4, 'red'), (r5, 'red'), (r1, 'blue'), (r2, 'red'), (r3, 'red')]
        self.assertListEqual(expected_result, result)
        # Can also set for a specific bunch of nodes
        nodes = ["r1", "r2", "r3"]
        ank_utils.set_node_default(g_phy, nodes, role="core")
        result = [(n, n.get("role")) for n in g_phy]
        expected_result = [(r4, None), (r5, None), (r1, 'core'), (r2, 'core'), (r3, 'core')]
        self.assertListEqual(expected_result, result)

result = [n.get("color") for n in g_phy]
        expected_result = [None, None, None, None, None]
        self.assertEqual(expected_result, result)
        ank_utils.set_node_default(g_in, color="red")
        ank_utils.copy_attr_from(g_in, g_phy, "color")
        result = [n.get("color") for n in g_phy]
        expected_result = ['red', 'red', 'red', 'red', 'red']
        self.assertListEqual(expected_result, result)
        # Can specify a default value if unset
        nodes = ["r1", "r2", "r3"]
        r1 = g_in.node('r1')
        r2 = g_in.node('r2')
        r3 = g_in.node('r3')
        r4 = g_in.node('r4')
        r5 = g_in.node('r5')
        ank_utils.set_node_default(g_in, nodes, role="core")
        ank_utils.copy_attr_from(g_in, g_phy, "role", default="edge")
        result = [(n, n.get("role")) for n in g_phy]
        expected_result = [(r4, 'edge'), (r5, 'edge'), (r1, 'core'),
                           (r2, 'core'), (r3, 'core')]

        self.assertListEqual(expected_result, result)
        # Can specify the remote attribute to set
        ank_utils.copy_attr_from(g_in, g_phy, "role",
                                "device_role", default="edge")
        result = [(n, n.get('device_role')) for n in g_phy]
        expected_result = [(n, n.get('role') if n.get('role') else 'edge')
                           for n in g_in]
        self.assertListEqual(expected_result, result)
        # Can specify the type to cast to
        g_in.update(memory = "32")
        ank_utils.copy_attr_from(g_in, g_phy, "memory", type=int)

def test_set_node_default(self):
        anm = autonetkit.topos.house()
        g_phy = anm['phy']
        r1 = g_phy.node("r1")
        r2 = g_phy.node("r2")
        r3 = g_phy.node("r3")
        r4 = g_phy.node("r4")
        r5 = g_phy.node("r5")
        r1.set("color", "blue")
        result = [(n, n.get("color")) for n in g_phy]
        expected_result  = [(r4, None), (r5, None), (r1, 'blue'), (r2, None), (r3, None)]
        self.assertListEqual(expected_result, result)
        ank_utils.set_node_default(g_phy, color="red")
        result = [(n, n.get("color")) for n in g_phy]
        expected_result = [(r4, 'red'), (r5, 'red'), (r1, 'blue'), (r2, 'red'), (r3, 'red')]
        self.assertListEqual(expected_result, result)
        # Can also set for a specific bunch of nodes
        nodes = ["r1", "r2", "r3"]
        ank_utils.set_node_default(g_phy, nodes, role="core")
        result = [(n, n.get("role")) for n in g_phy]
        expected_result = [(r4, None), (r5, None), (r1, 'core'), (r2, 'core'), (r3, 'core')]
        self.assertListEqual(expected_result, result)

g_phy.data['vxlan_global_config'] = g_in.data['vxlan_global_config']

    if g_phy.data.enable_routing is None:
        g_in.data.enable_routing = True  # default if not set


    g_phy.add_nodes_from(g_in, retain=['name', 'label', 'update', 'device_type', 'devsubtype',
                                       'asn', 'specified_int_names', 'x', 'y',
                                       'device_subtype', 'platform', 'host', 'syntax',
                                       'profile', 'syslog', 'vpc-peer',
                                        'vxlan_vni_configured'])

    if g_in.data.Creator == "Topology Zoo Toolset":
        ank_utils.copy_attr_from(g_in, g_phy, "Network")

    ank_utils.set_node_default(g_phy, Network=None)
    g_phy.add_edges_from(g_in.edges(type="physical"), retain=['link_type'])
    # TODO: make this automatic if adding to the physical graph?

    ank_utils.set_node_default(g_phy, use_ipv4=False, use_ipv6=False)
    ank_utils.copy_attr_from(g_in, g_phy, "custom_config_global",
                             dst_attr="custom_config")

    for node in g_phy:
        if node['input'].custom_config_loopback_zero:
            lo_zero_config = node['input'].custom_config_loopback_zero
            node.loopback_zero.custom_config = lo_zero_config
        custom_config_phy_ints = node['input'].custom_config_phy_ints
        for interface in node:
            if custom_config_phy_ints:
                interface.custom_config = custom_config_phy_ints
            specified_id = interface['input'].get("specified_id")

build_ipv4(anm, infrastructure=False)
        g_phy.update(g_phy, use_ipv4=False)

    # TODO: Create collision domain overlay for ip addressing - l2 overlay?
    if address_family == "None":
        log.info("IP addressing disabled, not allocating IPv6")
        anm.add_overlay("ipv6")  # create empty so rest of code follows
        g_phy.update(g_phy, use_ipv6=False)
    elif address_family in ("v6", "dual_stack"):
        build_ipv6(anm)
        g_phy.update(g_phy, use_ipv6=True)
    else:
        anm.add_overlay("ipv6")  # placeholder for compiler logic

    default_igp = g_in.data.igp or "ospf"
    ank_utils.set_node_default(g_in, igp=default_igp)
    ank_utils.copy_attr_from(g_in, g_phy, "igp")

    ank_utils.copy_attr_from(g_in, g_phy, "include_csr")

    try:
        from autonetkit_cisco import build_network as cisco_build_network
    except ImportError, error:
        log.debug("Unable to load autonetkit_cisco %s" % error)
    else:
        cisco_build_network.pre_design(anm)

    # log.info("Building IGP")
    from autonetkit.design.igp import build_igp
    build_igp(anm)

    # log.info("Building BGP")

g_phy.update(g_phy, use_ipv4=False)

    # TODO: Create collision domain overlay for ip addressing - l2 overlay?
    if address_family == "None":
        log.info("IP addressing disabled, not allocating IPv6")
        anm.add_overlay("ipv6")  # create empty so rest of code follows
        g_phy.update(g_phy, use_ipv6=False)
    elif address_family in ("v6", "dual_stack"):
        build_ipv6(anm)
        g_phy.update(g_phy, use_ipv6=True)
    else:
        anm.add_overlay("ipv6")  # placeholder for compiler logic
    assign_loopback_ip_pool(anm)
    #default_igp = g_in.data.igp or "ospf"
    default_igp = g_in.data.igp
    ank_utils.set_node_default(g_in, igp=default_igp)
    ank_utils.copy_attr_from(g_in, g_phy, "igp")

    ank_utils.copy_attr_from(g_in, g_phy, "include_csr")

    try:
        from autonetkit_cisco import build_network as cisco_build_network
    except ImportError, error:
        log.debug("Unable to load autonetkit_cisco %s" % error)
    else:
        cisco_build_network.pre_design(anm)

    # log.info("Building IGP")
    from autonetkit.design.igp import build_igp
    build_igp(anm)

    # log.info("Building BGP")

if g_in.data.vpcid_block:
        g_phy.data['vpcid_block'] = g_in.data['vpcid_block']

    if g_phy.data.enable_routing is None:
        g_in.data.enable_routing = True  # default if not set

    g_phy.add_nodes_from(g_in, retain=['label', 'update', 'device_type', 'devsubtype',
                                       'asn', 'specified_int_names', 'x', 'y',
                                       'device_subtype', 'platform', 'host', 'syntax',
                                       'profile', 'syslog'])

    if g_in.data.Creator == "Topology Zoo Toolset":
        ank_utils.copy_attr_from(g_in, g_phy, "Network")

    ank_utils.set_node_default(g_phy, Network=None)
    g_phy.add_edges_from(g_in.edges(type="physical"))
    # TODO: make this automatic if adding to the physical graph?

    ank_utils.set_node_default(g_phy, use_ipv4=False, use_ipv6=False)
    ank_utils.copy_attr_from(g_in, g_phy, "custom_config_global",
                             dst_attr="custom_config")

    for node in g_phy:
        if node['input'].custom_config_loopback_zero:
            lo_zero_config = node['input'].custom_config_loopback_zero
            node.loopback_zero.custom_config = lo_zero_config
        custom_config_phy_ints = node['input'].custom_config_phy_ints
        for interface in node:
            if custom_config_phy_ints:
                interface.custom_config = custom_config_phy_ints
            specified_id = interface['input'].get("specified_id")

build_ipv4(anm, infrastructure=False)
            g_phy.update(g_phy, use_ipv4=False)

        # TODO: Create collision domain overlay for ip addressing - l2 overlay?
        if address_family == "None":
            log.info("IP addressing disabled, not allocating IPv6")
            anm.add_overlay("ipv6")  # create empty so rest of code follows
            g_phy.update(g_phy, use_ipv6=False)
        elif address_family in ("v6", "dual_stack"):
            build_ipv6(anm)
            g_phy.update(g_phy, use_ipv6=True)
        else:
            anm.add_overlay("ipv6")  # placeholder for compiler logic

        default_igp = g_in.data.igp or "ospf"
        ank_utils.set_node_default(g_in, igp=default_igp)
        ank_utils.copy_attr_from(g_in, g_phy, "igp")

        ank_utils.copy_attr_from(g_in, g_phy, "include_csr")

        # log.info("Building IGP")
        from autonetkit.design.igp import build_igp
        build_igp(anm)

        # log.info("Building BGP")
        from autonetkit.design.bgp import build_bgp
        build_bgp(anm)
        # autonetkit.update_vis(anm)

        from autonetkit.design.mpls import mpls_te, mpls_oam
        mpls_te(anm)
        mpls_oam(anm)

if g_phy.data.enable_routing is None:
        g_in.data.enable_routing = True  # default if not set

    g_phy.add_nodes_from(g_in, retain=['label', 'update', 'device_type', 'devsubtype',
                                       'asn', 'specified_int_names', 'x', 'y',
                                       'device_subtype', 'platform', 'host', 'syntax',
                                       'profile', 'syslog'])

    if g_in.data.Creator == "Topology Zoo Toolset":
        ank_utils.copy_attr_from(g_in, g_phy, "Network")

    ank_utils.set_node_default(g_phy, Network=None)
    g_phy.add_edges_from(g_in.edges(type="physical"))
    # TODO: make this automatic if adding to the physical graph?

    ank_utils.set_node_default(g_phy, use_ipv4=False, use_ipv6=False)
    ank_utils.copy_attr_from(g_in, g_phy, "custom_config_global",
                             dst_attr="custom_config")

    for node in g_phy:
        if node['input'].custom_config_loopback_zero:
            lo_zero_config = node['input'].custom_config_loopback_zero
            node.loopback_zero.custom_config = lo_zero_config
        custom_config_phy_ints = node['input'].custom_config_phy_ints
        for interface in node:
            if custom_config_phy_ints:
                interface.custom_config = custom_config_phy_ints
            specified_id = interface['input'].get("specified_id")
            if specified_id:
                interface.specified_id = specified_id  # map across

    #TODO: tidy this code up