*
   * @since 20.0 (varargs overload since 2.0)
   */
  public static void checkArgument(
      boolean expression, String errorMessageTemplate, char p1, char p2) {
    if (!expression) {
      throw new IllegalArgumentException(lenientFormat(errorMessageTemplate, p1, p2));
    }
  }

  /**

    assertEquals("[(bar,1)=b, (foo,1)=a, (foo,3)=c]", table.cellSet().toString());
  }

  public void testRowKeySetToString_ordered() {
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    assertEquals("[bar, foo]", table.rowKeySet().toString());
  }

  public void testValuesToString_ordered() {
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');

    assertSize(3);
  }

  public void testPutNullReplace() {
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');

    if (supportsNullValues()) {
      assertEquals((Character) 'b', table.put("bar", 1, nullableCellValue(null)));
      assertNull(table.get("bar", 1));
    } else {
      try {
        table.put("bar", 1, nullableCellValue(null));
        fail();
      } catch (NullPointerException expected) {

@ElementTypesAreNonnullByDefault
public class TreeTraverserTest extends TestCase {
  private static class Node {
    final char value;

    Node(char value) {
      this.value = value;
    }
  }

  private static final class Tree extends Node {
    final List<Tree> children;

    public Tree(char value, Tree... children) {
      super(value);
      this.children = Arrays.asList(children);
    }
  }

    assertEquals(Arrays.asList(4, 5), multimap.get("bar"));
    assertEquals(6, multimap.size());
  }

  public void testBuilderPutAllMultimapWithDuplicates() {
    Multimap<String, Integer> toPut = LinkedListMultimap.create();
    toPut.put("foo", 1);
    toPut.put("bar", 4);
    toPut.put("foo", 2);
    toPut.put("foo", 1);
    toPut.put("bar", 5);

    builder.putAll("foo", Arrays.asList(1, 2, 3));
    builder.putAll("bar", Arrays.asList(4, 5));
    builder.putAll("foo", Arrays.asList(6, 7));
    Multimap<String, Integer> multimap = builder.build();
    assertEquals(ImmutableSet.of(1, 2, 3, 6, 7), multimap.get("foo"));
    assertEquals(ImmutableSet.of(4, 5), multimap.get("bar"));
    assertEquals(7, multimap.size());
  }

          "",
          " ",
          "127.0.0.1",
          "::1",
          "13",
          "abc.12c",
          "foo-.com",
          "_bar.quux",
          "foo+bar.com",
          "foo!bar.com",
          ".foo.com",
          "..bar.com",
          "baz..com",
          "..quiffle.com",
          "fleeb.com..",
          ".",
          "..",
          "...",

    Iterator<String> iterator = Collections.singletonList("foo").iterator();
    assertEquals("foo", Iterators.getOnlyElement(iterator, "bar"));
  }

  public void testGetOnlyElement_withDefault_empty() {
    Iterator<String> iterator = Iterators.emptyIterator();
    assertEquals("bar", Iterators.getOnlyElement(iterator, "bar"));
  }

  public void testGetOnlyElement_withDefault_empty_null() {

    }
    assertSize(0);
  }

  @Override
  public void testPutAllTable() {
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    Table<String, Integer, Character> other = HashBasedTable.create();
    other.put("foo", 1, 'd');
    other.put("bar", 2, 'e');
    other.put("cat", 2, 'f');
    try {
      table.putAll(other);
      fail("Expected UnsupportedOperationException");

  }

  public void testToString() {
    Multimap<String, Integer> multimap = create();
    multimap.put("foo", 3);
    multimap.put("bar", 1);
    multimap.putAll("foo", Arrays.asList(-1, 2, 4));
    multimap.putAll("bar", Arrays.asList(2, 3));
    multimap.put("foo", 1);
    assertEquals("{bar=[3, 2, 1], foo=[4, 3, 2, 1, -1]}", multimap.toString());
  }

  public void testGetComparator() {