code: public Set<TypedEdge<T>> edges(T t) {
          Set<TypedEdge<T>> edges =
              new HashSet<TypedEdge<T>>();
          for (SparseTypedEdgeSet<T> set : vertexToEdges.valueCollection()) {
              if (set.types().contains(t)) 
                  edges.addAll(set.getEdges(t));
          }
          return edges;
      }
docs: {@inheritDoc}