* #transform}.
   *
   * @param exceptionType the exception type that triggers use of {@code fallback}. The exception
   *     type is matched against the input's exception. "The input's exception" means the cause of
   *     the {@link ExecutionException} thrown by {@code input.get()} or, if {@code get()} throws a
   *     different kind of exception, that exception itself. To avoid hiding bugs and other

   1. Definitions.

      "License" shall mean the terms and conditions for use, reproduction,
      and distribution as defined by Sections 1 through 9 of this document.

      "Licensor" shall mean the copyright owner or entity authorized by
      the copyright owner that is granting the License.

      "Legal Entity" shall mean the union of the acting entity and all

   *
   * If we pick a function that goes /below/ that horizontal line, it means that we reduce the area
   * of the function, thus time. Thus, the RateLimiter becomes /faster/ after a period of
   * underutilization. If, on the other hand, we pick a function that goes /above/ that horizontal
   * line, then it means that the area (time) is increased, thus storedPermits are more costly than

   * interface, whose return type {@code AnnotatedType[]} is also new in Java 8. That means that we
   * cannot implement that interface in source code in a way that will compile on both Java 7 and
   * Java 8. If we include the {@code getAnnotatedBounds()} method then its return type means it
   * won't compile on Java 7, while if we don't include the method then the compiler will complain

   * Generation, described in Knuth's "The Art of Computer Programming", Volume 4, Chapter 7,
   * Section 7.2.1.2. The iteration order follows the lexicographical order. This means that the
   * first permutation will be in ascending order, and the last will be in descending order.
   *
   * <p>Duplicate elements are considered equal. For example, the list [1, 1] will have only one

    assertEquals(Arrays.toString(events), stopwatch.readEventsAndClear());
  }

  /**
   * The stopwatch gathers events and presents them as strings. R0.6 means a delay of 0.6 seconds
   * caused by the (R)ateLimiter U1.0 means the (U)ser caused the stopwatch to sleep for a second.
   */
  static class FakeStopwatch extends SleepingStopwatch {
    long instant = 0L;

     *
     * <p>If the Thread in use is interrupted before or during execution of the tasks in {@link
     * #queue}, the Executor will complete its tasks, and then restore the interruption. This means
     * that once the Thread returns to the Executor that this Executor composes, the interruption
     * will still be present. If the composed Executor is an ExecutorService, it can respond to

import java.util.Set;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A series of tests that support asserting that collections cannot be modified, either through
 * direct or indirect means.
 *
 * @author Robert Konigsberg
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public class UnmodifiableCollectionTests {

  public static void assertMapEntryIsUnmodifiable(Entry<?, ?> entry) {
    try {

        IllegalArgumentException.class,
        () -> Traverser.forGraph(createDirectedGraph()).breadthFirst('a'));
  }

  /**
   * Checks that the elements of the iterable are calculated on the fly. Concretely, that means that
   * {@link SuccessorsFunction#successors(Object)} can only be called for a subset of all nodes.
   */
  @Test
  public void forGraph_breadthFirstIterable_emptyGraph() {
    assertEqualCharNodes(

  //
  // - @PolyNull means "@Nullable or @Nonnull"
  //   (That would be unsound for an input Iterable<@Nullable Foo>. So, if we wanted to use
  //   @PolyNull, we would have to restrict this method to non-null <T>. But it has users who pass
  //   iterables with null elements.)
  //
  // - @JointlyNullable means "@Nullable or no annotation"
  @CheckForNull