start by opening a new issue describing the bug or feature you're intending to
fix. Even if you think it's relatively minor, it's helpful to know what people
are working on. And as mentioned above, API changes should be discussed
thoroughly before moving to code.

Some examples of types of pull requests that are immediately helpful:

  - Fixing a bug without changing a public API.
  - Fixing or improving documentation.

   * that tests of {@link CopyOnWriteArrayList} can suppress them with {@code
   * FeatureSpecificTestSuiteBuilder.suppressing()} until <a
   * href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6570631">Sun bug 6570631</a> is fixed.
   */
  @J2ktIncompatible
  @GwtIncompatible // reflection
  public static Method getSubListOriginalListSetAffectsSubListMethod() {

      }
      if (
      /*
       * At least one of the classes nested inside TypeResolverTest triggers a bug under older JDKs:
       * https://bugs.openjdk.org/browse/JDK-8215328 -> https://bugs.openjdk.org/browse/JDK-8215470
       * https://github.com/google/guava/blob/4f12c5891a7adedbaa1d99fc9f77d8cc4e9da206/guava-tests/test/com/google/common/reflect/TypeResolverTest.java#L201

      }
      if (
      /*
       * At least one of the classes nested inside TypeResolverTest triggers a bug under older JDKs:
       * https://bugs.openjdk.org/browse/JDK-8215328 -> https://bugs.openjdk.org/browse/JDK-8215470
       * https://github.com/google/guava/blob/4f12c5891a7adedbaa1d99fc9f77d8cc4e9da206/guava-tests/test/com/google/common/reflect/TypeResolverTest.java#L201

   * Returns the {@link Method} instance for {@link #testPutAll_nullKeyUnsupported()} so that tests
   * can suppress it with {@code FeatureSpecificTestSuiteBuilder.suppressing()} until <a
   * href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=5045147">Sun bug 5045147</a> is fixed.
   */
  @J2ktIncompatible
  @GwtIncompatible // reflection
  public static Method getPutAllNullKeyUnsupportedMethod() {

@ReflectionSupport(value = ReflectionSupport.Level.FULL)
@ElementTypesAreNonnullByDefault
// Some Android 5.0.x Samsung devices have bugs in JDK reflection APIs that cause
// getDeclaredField to throw a NoSuchFieldException when the field is definitely there.
// Since this class only needs CAS on one field, we can avoid this bug by extending AtomicReference
// instead of using an AtomicReferenceFieldUpdater. This reference stores Thread instances

   * href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6409434">Sun bug 6409434</a> is fixed.
   * It's unclear whether nulls were to be permitted or forbidden, but presumably the eventual fix
   * will be to permit them, as it seems more likely that code would depend on that behavior than on
   * the other. Thus, we say the bug is in add(), which fails to support null.
   */
  @J2ktIncompatible

  @J2ktIncompatible
  @GwtIncompatible // NullPointerTester
  public void testNulls() throws NoSuchMethodException {
    NullPointerTester tester = new NullPointerTester();
    // Necessary until JDK15:
    // https://bugs.openjdk.org/browse/JDK-8202469
    tester.ignore(Equivalence.class.getMethod("wrap", Object.class));

    tester.testAllPublicStaticMethods(Equivalence.class);
    tester.testAllPublicInstanceMethods(Equivalence.equals());

   * Returns the {@link Method} instance for {@link #testAddAll_nullUnsupported()} so that tests can
   * suppress it with {@code FeatureSpecificTestSuiteBuilder.suppressing()} until <a
   * href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=5045147">Sun bug 5045147</a> is fixed.
   */
  @J2ktIncompatible
  @GwtIncompatible // reflection
  public static Method getAddAllNullUnsupportedMethod() {

   * tests of {@link CopyOnWriteArraySet} can suppress it with {@code
   * FeatureSpecificTestSuiteBuilder.suppressing()} until <a
   * href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6570575">Sun bug 6570575</a> is fixed.
   */
  @J2ktIncompatible
  @GwtIncompatible // reflection
  public static Method getListIteratorFullyModifiableMethod() {