code: public void addEdge(final Collection<HypergraphNode<T>> nodes) {
      final HypergraphEdge<T> edge = new HypergraphEdge<>(nodes);
      this.nodes.addAll(nodes);
      this.edges.add(edge);
    }
docs: Adds an edges to the hypergraph.  The edge is represented by its connected nodes.
  @param nodes the nodes of the edge