public enum Modifiability {
    NONE, // immutable lists
    BY_ELEMENT, // elements can change (set), but not structure
    DIRECT_ONLY, // Element can be added and removed only via direct calls, not through iterators
    ALL // Elements can be added and removed as well as modified.
  }

  /** Handles the creation of lists needed for the tests */
  public abstract static class ListExample {

    private final String name;

 */

package com.google.common.cache;

import com.google.common.annotations.GwtCompatible;

/**
 * An object that can receive a notification when an entry is removed from a cache. The removal
 * resulting in notification could have occurred to an entry being manually removed or replaced, or
 * due to eviction resulting from timed expiration, exceeding a maximum size, or garbage collection.
 *

      --edgeCount;
    }
    if (isDirected()) { // In undirected graphs, the successor and predecessor sets are equal.
      // Since views are returned, we need to copy the predecessors that will be removed.
      // Thus we avoid modifying the underlying view while iterating over it.
      for (N predecessor : ImmutableList.copyOf(connections.predecessors())) {
        // requireNonNull is safe because the node is a predecessor.

  /**
   * Path of extension directory or directories.
   *
   * @deprecated This property was <a
   *     href="https://openjdk.java.net/jeps/220#Removed:-The-extension-mechanism">deprecated</a> in
   *     Java 8 and removed in Java 9. We do not plan to remove this API from Guava, but if you are
   *     using it, it is probably not doing what you want.
   */
  @Deprecated
  JAVA_EXT_DIRS("java.ext.dirs"),

   *
   * <p>This method refines {@link Collection#remove} to further specify that it <b>may not</b>
   * throw an exception in response to {@code element} being null or of the wrong type.
   *
   * <p>To both remove the element and obtain the previous count of that element, use {@link
   * #remove(Object, int) remove}{@code (element, 1)} instead.
   *
   * @param element the element to remove one occurrence of

   * creation and removal (including automatic removal of zeroes). If the modification of an
   * AtomicInteger results in zero, we compareAndSet the value to zero; if that succeeds, we remove
   * the entry from the Map. If another operation sees a zero in the map, it knows that the entry is
   * about to be removed, so this operation may remove it (often by replacing it with a new
   * AtomicInteger).
   */

public class SetRemoveTester<E> extends AbstractSetTester<E> {
  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testRemove_present() {
    getSet().remove(e0());
    assertFalse(
        "After remove(present) a set should not contain the removed element.",
        getSet().contains(e0()));
  }

  /**
   * Path of extension directory or directories.
   *
   * @deprecated This property was <a
   *     href="https://openjdk.java.net/jeps/220#Removed:-The-extension-mechanism">deprecated</a> in
   *     Java 8 and removed in Java 9. We do not plan to remove this API from Guava, but if you are
   *     using it, it is probably not doing what you want.
   */
  @Deprecated
  JAVA_EXT_DIRS("java.ext.dirs"),

    assertEquals("B", peekingIterator.peek());

    /* Should complain on attempt to remove() after peek(). */
    try {
      peekingIterator.remove();
      fail("remove() should throw IllegalStateException after a peek()");
    } catch (IllegalStateException e) {
      /* expected */
    }

    assertEquals(
        "After remove() throws exception, peek should still be ok", "B", peekingIterator.peek());

   * this graph.
   *
   * <p>This is equal to the union of {@link #predecessors(Object)} and {@link #successors(Object)}.
   *
   * <p>If {@code node} is removed from the graph after this method is called, the {@code Set}
   * {@code view} returned by this method will be invalidated, and will throw {@code
   * IllegalStateException} if it is accessed in any way, with the following exceptions: