@GwtCompatible
@ElementTypesAreNonnullByDefault
public final class Collections2 {
  private Collections2() {}

  /**
   * Returns the elements of {@code unfiltered} that satisfy a predicate. The returned collection is
   * a live view of {@code unfiltered}; changes to one affect the other.
   *
   * <p>The resulting collection's iterator does not support {@code remove()}, but all other

      return null;
    }

    private static final long serialVersionUID = 0;
  }

  /**
   * Returns a view of the elements of {@code unfiltered} that satisfy a predicate. The returned
   * multiset is a live view of {@code unfiltered}; changes to one affect the other.
   *
   * <p>The resulting multiset's iterators, and those of its {@code entrySet()} and {@code

  @Override
  Set<N> nodes();

  /** Returns all edges in this graph. */
  @Override
  Set<EndpointPair<N>> edges();

  /**
   * Returns a live view of this graph as a {@link Graph}. The resulting {@link Graph} will have an
   * edge connecting node A to node B if this {@link ValueGraph} has an edge connecting A to B.
   */
  Graph<N> asGraph();

  //

  Set<N> nodes();

  /** Returns all edges in this network, in the order specified by {@link #edgeOrder()}. */
  Set<E> edges();

  /**
   * Returns a live view of this network as a {@link Graph}. The resulting {@link Graph} will have
   * an edge connecting node A to node B if this {@link Network} has an edge connecting A to B.
   *

@GwtCompatible
@ElementTypesAreNonnullByDefault
public final class Collections2 {
  private Collections2() {}

  /**
   * Returns the elements of {@code unfiltered} that satisfy a predicate. The returned collection is
   * a live view of {@code unfiltered}; changes to one affect the other.
   *
   * <p>The resulting collection's iterator does not support {@code remove()}, but all other

   *
   * @since 29.0
   */
  @Override
  ElementOrder<N> incidentEdgeOrder();

  //
  // Element-level accessors
  //

  /**
   * Returns a live view of the nodes which have an incident edge in common with {@code node} in
   * this graph.
   *
   * <p>This is equal to the union of {@link #predecessors(Object)} and {@link #successors(Object)}.
   *

import java.util.regex.Pattern;
import junit.framework.AssertionFailedError;
import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Tests for {@link ForwardingWrapperTester}. Live in a different package to detect reflection
 * access issues, if any.
 *
 * @author Ben Yu
 */
public class ForwardingWrapperTesterTest extends TestCase {

 *
 * <p>{@code Multiset} refines the specifications of several methods from {@code Collection}. It
 * also defines an additional query operation, {@link #count}, which returns the count of an
 * element. There are five new bulk-modification operations, for example {@link #add(Object, int)},
 * to add or remove multiple occurrences of an element at once, or to set the count of an element to

import java.util.regex.Pattern;
import junit.framework.AssertionFailedError;
import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Tests for {@link ForwardingWrapperTester}. Live in a different package to detect reflection
 * access issues, if any.
 *
 * @author Ben Yu
 */
public class ForwardingWrapperTesterTest extends TestCase {

 *       {@code fail}, {@code assertTrue}, etc.) It is OK (but not particularly recommended) for
 *       other code to use these forms too. Only the most typically used JUnit assertion methods are
 *       defined this way, but enough to live with.
 *   <li>If you override {@link #setUp} or {@link #tearDown}, make sure to invoke {@code
 *       super.setUp} and {@code super.tearDown} within them. These methods are used to clear and