throw new InvalidGraphElementException(this, v0, String.format("Duplicate element id #%d: Vertex[%s] <-> %s",
v0.getElementId(), v0, seen_ids.get(v0.getElementId())));
}
seen_ids.put(v0.getElementId(), v0);
all_partitions.addAll(v0.partitions);
all_partitions.addAll(v0.past_partitions);
for (MarkovEdge e : outbound) {
MarkovVertex v1 = this.getOpposite(v0, e);