module foo {
    yang-version 1;
    namespace "foo";
    prefix "foo";

    revision "2015-11-05" {
    }

    typedef ipv4-address-binary {
        type binary {
            length "4";
        }
    }

    typedef ipv6-address-binary {
        type binary {
            length "16";
        }
    }

    typedef ip-address-binary {
        type union {
            type ipv4-address-binary;
            type ipv6-address-binary;
        }
    }

    container root {
        leaf ip-address {
            type ip-address-binary;
        }
    }
}