class SequenceItem implements VertexDictionary {

    @Override
    public <V extends Vertex<?, ?>> V get(VertexLabel label) {
        Vertex<?, ?> vertex = contents.getOrDefault(label, contents.get(scoped(label)));

        if (vertex == null) {
            throw new IllegalArgumentException("Cannot find VertexLabel " + label);
        }
        return (V) vertex;
    }

    public  SequenceItem(int index, int uniqueSequenceIdentifier);
    public  SequenceItem(int index, int uniqueSequenceIdentifier, String sequenceName);

}