/** @see Graph#vertexSet() */
public Set<V> vertexSet() {
if (unmodifiableVertexSet == null) {
unmodifiableVertexSet = Collections.unmodifiableSet(specifics.getVertexSet());
}
return unmodifiableVertexSet;
}
/** @see Graph#removeVertex(Object) */
public boolean removeVertex(V v) {
if (containsVertex(v)) {
Set<E> touchingEdgesList = edgesOf(v);
// cannot iterate over list - will cause
// ConcurrentModificationException
removeAllEdges(new ArrayList<E>(touchingEdgesList));
specifics.getVertexSet().remove(v); // remove the vertex itself
return true;
} else {
return false;
}
}
/** @see Graph#containsVertex(Object) */
public boolean containsVertex(V v) {
return specifics.getVertexSet().contains(v);
}