public Set<E> outEdges(N node) {
    return delegate().outEdges(node);
  }

  @Override
  public EndpointPair<N> incidentNodes(E edge) {
    return delegate().incidentNodes(edge);
  }

  @Override
  public Set<E> adjacentEdges(E edge) {
    return delegate().adjacentEdges(edge);
  }

  @Override
  public int degree(N node) {
    return delegate().degree(node);
  }

  @Override

import javax.annotation.CheckForNull;

/**
 * A class to represent the set of edges connecting an (implicit) origin node to a target node.
 *
 * <p>The {@link #nodeToOutEdge} map means this class only works on networks without parallel edges.
 * See {@link MultiEdgesConnecting} for a class that works with parallel edges.
 *
 * @author James Sexton
 * @param <E> Edge parameter type
 */
@ElementTypesAreNonnullByDefault

                </mxCell>
                <mxCell id="8" style="edgeStyle=orthogonalEdgeStyle;rounded=0;orthogonalLoop=1;jettySize=auto;html=1;strokeWidth=3;exitX=0.092;exitY=1.01;exitDx=0;exitDy=0;dashed=1;exitPerimeter=0;" parent="1" edge="1">
                    <mxGeometry relative="1" as="geometry">
                        <Array as="points">
                            <mxPoint x="800" y="521"/>
                            <mxPoint x="800" y="560"/>

                </mxCell>
                <mxCell id="8" style="edgeStyle=orthogonalEdgeStyle;rounded=0;orthogonalLoop=1;jettySize=auto;html=1;strokeWidth=3;exitX=0.092;exitY=1.01;exitDx=0;exitDy=0;dashed=1;exitPerimeter=0;" parent="1" edge="1">
                    <mxGeometry relative="1" as="geometry">
                        <Array as="points">
                            <mxPoint x="800" y="521"/>
                            <mxPoint x="800" y="560"/>

      mutableValueGraph.addNode(node);
      return this;
    }

    /**
     * Adds an edge connecting {@code nodeU} to {@code nodeV} if one is not already present, and
     * sets a value for that edge to {@code value} (overwriting the existing value, if any).
     *
     * <p>If the graph is directed, the resultant edge will be directed; otherwise, it will be
     * undirected.
     *

import javax.annotation.CheckForNull;

/**
 * A class to represent the set of edges connecting an (implicit) origin node to a target node.
 *
 * <p>The {@link #outEdgeToNode} map allows this class to work on networks with parallel edges. See
 * {@link EdgesConnecting} for a class that is more efficient but forbids parallel edges.
 *
 * @author James Sexton
 * @param <E> Edge parameter type
 */
@ElementTypesAreNonnullByDefault

            List<String> cycle = visitCycle(graph, Collections.singleton(to), new HashMap<>(), new LinkedList<>());
            if (cycle != null) {
                // remove edge which introduced cycle
                throw new CycleDetectedException(
                        "Edge between '" + from + "' and '" + to + "' introduces to cycle in the graph", cycle);
            }
        }
    }

    private enum DfsState {
        VISITING,

        + nodes()
        + ", edges: "
        + edgeValueMap(this);
  }

  private static <N, V> Map<EndpointPair<N>, V> edgeValueMap(final ValueGraph<N, V> graph) {
    return Maps.asMap(
        graph.edges(),
        edge ->
            // requireNonNull is safe because the endpoint pair comes from the graph.
            requireNonNull(graph.edgeValueOrDefault(edge.nodeU(), edge.nodeV(), null)));
  }

        while (resultWithDoubleSelfLoop.hasNext()) {
          EndpointPair<N> edge = resultWithDoubleSelfLoop.next();
          if (edge.nodeU().equals(edge.nodeV())) {
            if (!alreadySeenSelfLoop.getAndSet(true)) {
              return edge;
            }
          } else {
            return edge;
          }
        }
        return endOfData();
      }
    };
  }

                    <mxGeometry relative="1" as="geometry"/>
                </mxCell>
                <mxCell id="20" style="edgeStyle=orthogonalEdgeStyle;rounded=0;orthogonalLoop=1;jettySize=auto;html=1;endArrow=none;endFill=0;strokeWidth=3;" parent="1" source="11" target="18" edge="1">
                    <mxGeometry relative="1" as="geometry"/>