innerCount++;
                    }
                }
                assertEquals(0, innerCount, "Inner iteration should not execute");
            }
            assertEquals(0, outerCount, "Outer iteration should not execute");
        }, "EmptyIterator should work correctly in nested iteration");
    }

    @Test
    @DisplayName("EmptyIterator should follow Iterator contract for empty collections")

                        try {
                            // Mix of success and failure
                            final int iteration = i;
                            String result = circuitBreaker.executeWithCircuitBreaker(() -> {
                                if ((threadId + iteration) % 10 == 0) {
                                    throw new RuntimeException("Simulated failure");
                                }

        // Verify iteration
        assertTrue(iterator.hasNext());
        assertSame(resource, iterator.next());
        assertFalse(iterator.hasNext());

        verify(filter, times(2)).accept(resource);
        verify(resource, times(2)).close();
    }

    @Test
    @DisplayName("Multiple iterations")
    void multipleIterations() {
        // Setup for three items

     * with each iteration, so this algorithm takes O(log(digits)) iterations.
     *
     * We start out with a double-precision approximation, which may be higher or lower than the
     * true value. Therefore, we perform at least one Newton iteration to get a guess that's
     * definitely >= floor(sqrt(x)), and then continue the iteration until we reach a fixed point.
     */
    BigInteger sqrt0;
    int log2 = log2(x, FLOOR);

   * described in the class documentation.
   *
   * @throws NullPointerException if any of {@code elements} is null
   * @since 6.0
   */
  public static <E> ImmutableMultiset<E> copyOf(E[] elements) {
    return copyFromElements(elements);
  }

  /**
   * Returns an immutable multiset containing the given elements, in the "grouped iteration order"

 * keys and values. The iteration order is preserved across non-distinct key values. For example,
 * for the following multimap definition:
 *
 * {@snippet :
 * Multimap<K, V> multimap = LinkedListMultimap.create();
 * multimap.put(key1, foo);
 * multimap.put(key2, bar);
 * multimap.put(key1, baz);
 * }
 *

        t.url = null; // Null URL
        t.numIter = 0; // No iterations to avoid NPE

        // Should not throw exception
        assertDoesNotThrow(() -> t.run(), "run() should handle null URL gracefully");
        assertEquals(1, t.numComplete, "numComplete should still be incremented");
    }

    @Test
    @DisplayName("run method handles zero iterations")
    void testRunWithZeroIterations() {

    assertEquals(2, copy.size());
    assertSame(copy, copy.iterator().next().member);
  }

  /*
   * The behavior of toString() and iteration is tested by LinkedHashMultiset,
   * which shares a lot of code with HashMultiset and has deterministic
   * iteration order.
   */

    }
  }

  /**
   * Returns an immutable set instance containing the given enum elements. Internally, the returned
   * set will be backed by an {@link EnumSet}.
   *
   * <p>The iteration order of the returned set follows the enum's iteration order, not the order in
   * which the elements are provided to the method.
   *
   * @param anElement one of the elements the set should contain

 * need for a distinct {@code ImmutableBiMultimap} type.
 *
 * <p><a id="iteration"></a>
 *
 * <p><b>Key-grouped iteration.</b> All view collections follow the same iteration order. In all
 * current implementations, the iteration order always keeps multiple entries with the same key
 * together. Any creation method that would customarily respect insertion order (such as {@link