}
    };
  }

  @Override
  public @Nullable N removeInEdge(E edge, boolean isSelfLoop) {
    if (!isSelfLoop) {
      return removeOutEdge(edge);
    }
    return null;
  }

  @Override
  public N removeOutEdge(E edge) {
    N node = super.removeOutEdge(edge);
    Multiset<N> adjacentNodes = getReference(adjacentNodesReference);
    if (adjacentNodes != null) {

import com.google.common.collect.Sets;
import java.util.Iterator;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * A class to facilitate the set returned by {@link Graph#edges()}.
 *
 * @author James Sexton
 */
abstract class EndpointPairIterator<N> extends AbstractIterator<EndpointPair<N>> {
  private final BaseGraph<N> graph;
  private final Iterator<N> nodeIterator;

   *
   * @return the value previously associated with the edge connecting {@code nodeU} to {@code
   *     nodeV}, or null if there was no such edge.
   * @throws IllegalArgumentException if the introduction of the edge would violate {@link
   *     #allowsSelfLoops()}
   */
  @CanIgnoreReturnValue
  @Nullable V putEdgeValue(N nodeU, N nodeV, V value);

  /**

 */

package com.google.common.graph;

import java.util.AbstractSet;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * Abstract base class for an incident edges set that allows different implementations of {@link
 * AbstractSet#iterator()}.
 */
abstract class IncidentEdgeSet<N> extends AbstractSet<EndpointPair<N>> {
  final N node;
  final BaseGraph<N> graph;

  @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);

  @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);

   *     #allowsSelfLoops()}
   */
  @CanIgnoreReturnValue
  boolean putEdge(N nodeU, N nodeV);

  /**
   * Adds an edge connecting {@code endpoints} (in the order, if any, specified by {@code
   * endpoints}) if one is not already present.
   *
   * <p>If this graph is directed, {@code endpoints} must be ordered and the added edge will be

      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.
     *

'right', 'top', 'bottom'],\n    /**\n     * @prop {number} padding=5\n     * Amount of pixel used to define a minimum distance between the boundaries\n     * and the popper. This makes sure the popper always has a little padding\n     * between the edges of its container\n     */\n    padding: 5,\n    /**\n     * @prop {String|HTMLElement} boundariesElement='scrollParent'\n     * Boundaries used by the modifier. Can be `scrollParent`, `window`,\n     * `viewport` or any DOM element.\n     */\n    boundariesElement:...

would never access <code>*p</code> or <code>*q</code>, but the rewritten program would.
And if the call contained synchronizing operations, then the original program
could establish happens before edges preceding the accesses
to <code>*p</code> and <code>*q</code>, but the rewritten program would not.
</p>

<p>
Not allowing a single read to observe multiple values means