*
       * TODO(b/112550045): Allocating a single, cheaper listener is (I think) only an optimization.
       * If we make some other optimizations, this one will no longer be necessary. The optimization
       * could actually hurt in some cases, as it forces us to keep all inputs in memory until the
       * final input completes.
       */

  }

  public void testFileTraverser_file() throws Exception {
    File file = newFile("some-file");

    assertThat(Files.fileTraverser().breadthFirst(file)).containsExactly(file);
  }

  public void testFileTraverser_singleFile() throws Exception {
    File file = newFile("some-file");

    assertThat(Files.fileTraverser().breadthFirst(rootDir)).containsExactly(rootDir, file);
  }

  }

  public void testFileTraverser_file() throws Exception {
    Path file = newFile("some-file");

    assertThat(MoreFiles.fileTraverser().breadthFirst(file)).containsExactly(file);
  }

  public void testFileTraverser_singleFile() throws Exception {
    Path file = newFile("some-file");

    assertThat(MoreFiles.fileTraverser().breadthFirst(rootDir)).containsExactly(rootDir, file);
  }

   * documentation for {@link Collection}:
   *
   * <blockquote>
   *
   * "Some collection implementations have restrictions on the elements that they may contain. For
   * example, some implementations prohibit null elements, and some have restrictions on the types
   * of their elements."
   *
   * </blockquote>
   */
  RESTRICTS_ELEMENTS,

  /**

  }

  public void testNewHashSetFromCollection() {
    HashSet<Integer> set = Sets.newHashSet(SOME_COLLECTION);
    verifySetContents(set, SOME_COLLECTION);
  }

  public void testNewHashSetFromIterable() {
    HashSet<Integer> set = Sets.newHashSet(SOME_ITERABLE);
    verifySetContents(set, SOME_ITERABLE);
  }

  public void testNewHashSetWithExpectedSizeSmall() {

     * @see DependencyCollector#collect(Session, Artifact)
     */
    @Nonnull
    DependencyCollectorResult collect(@Nonnull DependencyCollectorRequest request);

    /**
     * Collects the transitive dependencies of some artifacts and builds a dependency graph. Note that this operation is
     * only concerned about determining the coordinates of the transitive dependencies and does not actually resolve the
     * artifact files.
     *

    public void execute(MavenSession session) {
        lifecycleStarter.execute(session);
    }

    // These methods deal with construction intact Plugin object that look like they come from a standard
    // <plugin/> block in a Maven POM. We have to do some wiggling to pull the sources of information
    // together and this really shows the problem of constructing a sensible default configuration but

   * opening the data stream.
   *
   * <p>The default implementation returns {@link Optional#absent}. Some sources, such as a file,
   * may return a non-absent value. Note that in such cases, it is <i>possible</i> that this method
   * will return a different number of bytes than would be returned by reading all of the bytes (for
   * example, some special files may return a size of 0 despite actually having content when read).
   *

   * the discussion in the {@link #addListener} documentation. All its warnings about heavyweight
   * listeners are also applicable to heavyweight functions passed to this method.
   *
   * <p>This method is similar to {@link java.util.concurrent.CompletableFuture#exceptionally}. It
   * can also serve some of the use cases of {@link java.util.concurrent.CompletableFuture#handle}

   * {@code node}'s outgoing edges in the direction (if any) of the edge.
   *
   * <p>This is <i>not</i> the same as "all nodes reachable from {@code node} by following outgoing
   * edges". For that functionality, see {@link Graphs#reachableNodes(Graph, Object)}.
   *
   * <p>Some algorithms that operate on a {@code SuccessorsFunction} may produce undesired results