public void testOf() {
    assertMapEquals(ImmutableMap.of("one", 1), "one", 1);
    assertMapEquals(ImmutableMap.of("one", 1, "two", 2), "one", 1, "two", 2);
    assertMapEquals(
        ImmutableMap.of("one", 1, "two", 2, "three", 3), "one", 1, "two", 2, "three", 3);
    assertMapEquals(
        ImmutableMap.of("one", 1, "two", 2, "three", 3, "four", 4),
        "one",
        1,
        "two",
        2,
        "three",

    }

    @Override
    public Node getNode(org.eclipse.aether.graph.DependencyNode node) {
        return getNode(node, false);
    }

    @Override
    public Node getNode(org.eclipse.aether.graph.DependencyNode node, boolean verbose) {
        return allNodes.computeIfAbsent(node, n -> new DefaultNode(this, n, verbose));
    }

    @Nonnull
    @Override

   *   while (i.hasNext()) {
   *     foo(i.next());
   *   }
   * }
   * }</pre>
   *
   * <p>Failure to follow this advice may result in non-deterministic behavior.
   *
   * <p>Note that the generated multimap's {@link Multimap#removeAll} and {@link
   * Multimap#replaceValues} methods return collections that aren't synchronized.
   *

                            + validVersions + ". Building this project requires a newer version of Maven.",
                    tracker);

        } else if (olderThanAll) {
            // note this will not be hit for Maven 1.x project.xml as it is an incompatible schema
            addViolation(
                    problems,
                    Severity.FATAL,
                    Version.V20,

    Iterator<String> iterator = asList("one", "two").iterator();
    try {
      Iterators.getOnlyElement(iterator);
      fail();
    } catch (IllegalArgumentException expected) {
      assertThat(expected).hasMessageThat().isEqualTo("expected one element but was: <one, two>");
    }
  }

  public void testGetOnlyElement_noDefault_fiveElements() {