How to use

getReference

method

in

com.google.common.graph.DirectedMultiNetworkConnections

private Multiset<N> predecessorsMultiset() {
 Multiset<N> predecessors = getReference(predecessorsReference);
 if (predecessors == null) {
  predecessors = HashMultiset.create(inEdgeMap.values());
  predecessorsReference = new SoftReference<>(predecessors);
 }
 return predecessors;
}

private Multiset<N> successorsMultiset() {
 Multiset<N> successors = getReference(successorsReference);
 if (successors == null) {
  successors = HashMultiset.create(outEdgeMap.values());
  successorsReference = new SoftReference<>(successors);
 }
 return successors;
}

@Override
public void addOutEdge(E edge, N node) {
 super.addOutEdge(edge, node);
 Multiset<N> successors = getReference(successorsReference);
 if (successors != null) {
  checkState(successors.add(node));
 }
}

@Override
public void addInEdge(E edge, N node, boolean isSelfLoop) {
 super.addInEdge(edge, node, isSelfLoop);
 Multiset<N> predecessors = getReference(predecessorsReference);
 if (predecessors != null) {
  checkState(predecessors.add(node));
 }
}

private Multiset<N> predecessorsMultiset() {
 Multiset<N> predecessors = getReference(predecessorsReference);
 if (predecessors == null) {
  predecessors = HashMultiset.create(inEdgeMap.values());
  predecessorsReference = new SoftReference<>(predecessors);
 }
 return predecessors;
}

private Multiset<N> successorsMultiset() {
 Multiset<N> successors = getReference(successorsReference);
 if (successors == null) {
  successors = HashMultiset.create(outEdgeMap.values());
  successorsReference = new SoftReference<>(successors);
 }
 return successors;
}

@Override
public void addOutEdge(E edge, N node) {
 super.addOutEdge(edge, node);
 Multiset<N> successors = getReference(successorsReference);
 if (successors != null) {
  checkState(successors.add(node));
 }
}

@Override
public N removeInEdge(E edge, boolean isSelfLoop) {
 N node = super.removeInEdge(edge, isSelfLoop);
 Multiset<N> predecessors = getReference(predecessorsReference);
 if (predecessors != null) {
  checkState(predecessors.remove(node));
 }
 return node;
}

private Multiset<N> successorsMultiset() {
 Multiset<N> successors = getReference(successorsReference);
 if (successors == null) {
  successors = HashMultiset.create(outEdgeMap.values());
  successorsReference = new SoftReference<>(successors);
 }
 return successors;
}

private Multiset<N> predecessorsMultiset() {
 Multiset<N> predecessors = getReference(predecessorsReference);
 if (predecessors == null) {
  predecessors = HashMultiset.create(inEdgeMap.values());
  predecessorsReference = new SoftReference<>(predecessors);
 }
 return predecessors;
}

@Override
public N removeOutEdge(E edge) {
 N node = super.removeOutEdge(edge);
 Multiset<N> successors = getReference(successorsReference);
 if (successors != null) {
  checkState(successors.remove(node));
 }
 return node;
}

@Override
public void addInEdge(E edge, N node, boolean isSelfLoop) {
 super.addInEdge(edge, node, isSelfLoop);
 Multiset<N> predecessors = getReference(predecessorsReference);
 if (predecessors != null) {
  checkState(predecessors.add(node));
 }
}

@Override
public void addOutEdge(E edge, N node) {
 super.addOutEdge(edge, node);
 Multiset<N> successors = getReference(successorsReference);
 if (successors != null) {
  checkState(successors.add(node));
 }
}

@Override
public void addInEdge(E edge, N node, boolean isSelfLoop) {
 super.addInEdge(edge, node, isSelfLoop);
 Multiset<N> predecessors = getReference(predecessorsReference);
 if (predecessors != null) {
  checkState(predecessors.add(node));
 }
}

@Override
public N removeInEdge(E edge, boolean isSelfLoop) {
 N node = super.removeInEdge(edge, isSelfLoop);
 Multiset<N> predecessors = getReference(predecessorsReference);
 if (predecessors != null) {
  checkState(predecessors.remove(node));
 }
 return node;
}

@Override
public N removeOutEdge(E edge) {
 N node = super.removeOutEdge(edge);
 Multiset<N> successors = getReference(successorsReference);
 if (successors != null) {
  checkState(successors.remove(node));
 }
 return node;
}

@Override
public N removeOutEdge(E edge) {
 N node = super.removeOutEdge(edge);
 Multiset<N> successors = getReference(successorsReference);
 if (successors != null) {
  checkState(successors.remove(node));
 }
 return node;
}

@Override
public N removeInEdge(E edge, boolean isSelfLoop) {
 N node = super.removeInEdge(edge, isSelfLoop);
 Multiset<N> predecessors = getReference(predecessorsReference);
 if (predecessors != null) {
  checkState(predecessors.remove(node));
 }
 return node;
}

private Multiset<N> successorsMultiset() {
 Multiset<N> successors = getReference(successorsReference);
 if (successors == null) {
  successors = HashMultiset.create(outEdgeMap.values());
  successorsReference = new SoftReference<>(successors);
 }
 return successors;
}

@Override
public N removeOutEdge(E edge) {
 N node = super.removeOutEdge(edge);
 Multiset<N> successors = getReference(successorsReference);
 if (successors != null) {
  checkState(successors.remove(node));
 }
 return node;
}