checkResult(J, ITERABLE_123, "1-2-3");

    try {
      J.join(ITERABLE_NULL);
      fail();
    } catch (NullPointerException expected) {
    }
    try {
      J.join(ITERABLE_1_NULL_2);
      fail();
    } catch (NullPointerException expected) {
    }

    try {
      J.join(ITERABLE_NULL.iterator());
      fail();
    } catch (NullPointerException expected) {
    }
    try {

        fail("Encoding $component $codePoint using $encoding")
      }
      return
    }

    // Check that the URI and HttpURL have the exact same escaping.
    if (toAndFromUri != httpUrl) {
      fail("Encoding $component $codePoint using $encoding")
    }
    if (uri.toString() != httpUrl.toString()) {
      fail("Encoding $component $codePoint using $encoding")
    }

      put(e3());
      iterator.next();
      fail("Expected ConcurrentModificationException");
    } catch (ConcurrentModificationException expected) {
      // success
    }
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  public void testPut_unsupportedNotPresent() {
    try {
      put(e3());
      fail("put(notPresent, value) should throw");

      assertInvariants(map);
      try {
        iterator.remove();
        fail("Expected IllegalStateException.");
      } catch (IllegalStateException expected) {
      }
    } else {
      iterator.next();
      try {
        iterator.remove();
        fail("Expected UnsupportedOperationException.");
      } catch (UnsupportedOperationException expected) {
      }
    }

      getList().add(0, e3());
      iterator.next();
      fail("Expected ConcurrentModificationException");
    } catch (ConcurrentModificationException expected) {
      // success
    }
  }

  @ListFeature.Require(absent = SUPPORTS_ADD_WITH_INDEX)
  public void testAddAtIndex_unsupportedNotPresent() {
    try {
      getList().add(0, e3());
      fail("add(n, notPresent) should throw");

    // The opposite order should fail (Policies.THROW).
    PotentialDeadlockException firstException = null;
    lockB.lock();
    PotentialDeadlockException expected =
        assertThrows(PotentialDeadlockException.class, () -> lockA.lock());
    checkMessage(expected, "LockB -> LockA", "LockA -> LockB");
    firstException = expected;
    // Second time should also fail, with a cached causal chain.

    try {
      iterator.next();
      fail("no exception thrown");
    } catch (NoSuchElementException expected) {
    }
    try {
      iterator.previous();
      fail("no exception thrown");
    } catch (NoSuchElementException expected) {
    }
    try {
      iterator.remove();
      fail("no exception thrown");
    } catch (UnsupportedOperationException expected) {
    }

                    try {
                      peeker.getDone(input2Failed);
                      fail("Peeker.getDone() should fail for failed inputs");
                    } catch (ExecutionException expected) {
                    }
                    try {
                      peeker.getDone(nonInput);
                      fail("Peeker should not be able to peek into non-input ClosingFuture.");

    try {
      diff1.entriesInCommon().put(7, "x");
      fail();
    } catch (UnsupportedOperationException expected) {
    }
    try {
      diff1.entriesOnlyOnLeft().put(7, "x");
      fail();
    } catch (UnsupportedOperationException expected) {
    }
    try {
      diff1.entriesOnlyOnRight().put(7, "x");
      fail();
    } catch (UnsupportedOperationException expected) {
    }
  }

      // One more than maximum value
      UnsignedInts.decode("0xfffffffff");
      fail();
    } catch (NumberFormatException expected) {
    }

    try {
      UnsignedInts.decode("-5");
      fail();
    } catch (NumberFormatException expected) {
    }

    try {
      UnsignedInts.decode("-0x5");
      fail();
    } catch (NumberFormatException expected) {
    }

    try {