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

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

  }

  public void testParanoidHashBytes() {
    HashFn hf =
        new HashFn() {
          @Override
          public byte[] hash(byte[] input, int seed) {
            return murmur3_32(seed).hashBytes(input).asBytes();
          }
        };
    // Murmur3A, MurmurHash3 for x86, 32-bit (MurmurHash3_x86_32)
    // https://github.com/aappleby/smhasher/blob/master/src/main.cpp

    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <!--
    Some tests need reflective access to the internals of these packages. It is only the
    tests themselves and not the code being tested that needs that access, though there's no
    obvious way to ensure that.

    We could consider arranging things so that only the tests we know need this would get

  }

  public void testParanoidHashBytes() {
    HashFn hf =
        new HashFn() {
          @Override
          public byte[] hash(byte[] input, int seed) {
            return murmur3_32(seed).hashBytes(input).asBytes();
          }
        };
    // Murmur3A, MurmurHash3 for x86, 32-bit (MurmurHash3_x86_32)
    // https://github.com/aappleby/smhasher/blob/master/src/main.cpp

        assertEquals(longMessage, exception.getMessage());
        assertNull(exception.getCause());
    }

    @Test
    public void test_constructor_withNestedCause() {
        // Test constructor with nested exception causes
        Exception rootCause = new IllegalStateException("Root cause");
        Exception middleCause = new RuntimeException("Middle cause", rootCause);
        String message = "Top level dictionary error";

        mockPipeIn.lock = new Object();

        byte[] buffer = new byte[10];
        int bufferIndex = 0;
        int len = 10;

        // Call the method to be tested
        int result = response.readDataWireFormat(buffer, bufferIndex, len);

        // Verify the result
        assertEquals(len, result, "readDataWireFormat should return the length of data read.");

Just functions that look the same as the *path operation functions*.

But still, it is very powerful, and allows you to declare arbitrarily deeply nested dependency "graphs" (trees).

/// tip

All this might not seem as useful with these simple examples.

But you will see how useful it is in the chapters about **security**.

 * <ul>
 *   <li>Debugging and troubleshooting of request flows</li>
 *   <li>Audit logging of operations</li>
 *   <li>Performance monitoring of nested operations</li>
 * </ul>
 *
 * <p>This interface is designed to be extended by specific request types that handle
 * different Maven operations. All implementations must be immutable to ensure thread safety

    }

    /**
     * Gets a nested Map from the map.
     *
     * @param map The source map
     * @param key The key to look up
     * @return The nested Map, or null if the key doesn't exist or value is not a Map
     */
    @SuppressWarnings("unchecked")

    public void setGroupCacheExpiry(final long groupCacheExpiry) {
        this.groupCacheExpiry = groupCacheExpiry;
    }

    /**
     * Sets the maximum group depth for nested group processing.
     * @param maxGroupDepth The maximum depth for nested groups.
     */
    public void setMaxGroupDepth(final int maxGroupDepth) {
        this.maxGroupDepth = maxGroupDepth;
    }

    @Override