}, "EmptyIterator should work correctly in nested iteration");
    }

    @Test
    @DisplayName("EmptyIterator should follow Iterator contract for empty collections")
    void testIteratorContract() {
        // Given - typical Iterator usage pattern

        // When & Then - verify empty collection behavior

    limitation, court costs and reasonable attorneys' fees and expenses.
    The application of the United Nations Convention on Contracts for
    the International Sale of Goods is expressly excluded. Any law or
    regulation which provides that the language of a contract shall be
    construed against the drafter shall not apply to this License. You
    agree that You alone are responsible for compliance with the United

      return b == null ? null : checkNotNull(doBackward(b));
    } else {
      return unsafeDoBackward(b);
    }
  }

  /*
   * LegacyConverter violates the contract of Converter by allowing its doForward and doBackward
   * methods to accept null. We could avoid having unchecked casts in Converter.java itself if we

other entities that control, are controlled by, or are under common control with that entity. For the purposes of this definition, "control" means (i) the power, direct or indirect, to cause the direction or management of such entity, whether by contract or otherwise, or (ii) ownership of fifty percent (50%) or more of the outstanding shares, or (iii) beneficial ownership of such entity. "You" (or "Your") shall mean an individual or Legal Entity exercising permissions granted by this License. "Source"...

            // Simple test implementation - not used in these tests
            return 0;
        }
    }

    @Nested
    @DisplayName("Interface Contract Tests")
    class InterfaceContractTests {

        @Test
        @DisplayName("Should implement FileSystemInformation interface")
        void shouldImplementFileSystemInformation() {

   *
   * <p>Note that if the given output stream was not empty or is modified after the {@code
   * ByteArrayDataOutput} is created, the contract for {@link ByteArrayDataOutput#toByteArray} will
   * not be honored (the bytes returned in the byte array may not be exactly what was written via
   * calls to {@code ByteArrayDataOutput}).
   *
   * @since 17.0
   */

    Collections.shuffle(hashCodes);
    HashCode hashCode2 = Hashing.combineUnordered(hashCodes);

    assertEquals(hashCode1, hashCode2);
  }

  // This isn't specified by contract, but it'll still be nice to know if this behavior changes.
  public void testConcatenating_equals() {
    new EqualsTester()
        .addEqualityGroup(Hashing.concatenating(asList(Hashing.md5())))

            return size;
        }

        @Override
        public int size() {
            return size;
        }
    }

    @Nested
    @DisplayName("Interface Contract Tests")
    class InterfaceContractTests {

        @Test
        @DisplayName("Interface should be correctly implemented by mock")
        void testInterfaceImplementation() {

SHALL HAVE ANY LIABILITY FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING WITHOUT LIMITATION LOST
PROFITS), HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OR DISTRIBUTION OF THE PROGRAM OR THE
EXERCISE OF ANY RIGHTS GRANTED HEREUNDER, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES.

It has the same fields as `HeroBase`, so it won't include `secret_name`.

Finally, the identity of our heroes is protected! 🥷

It also re-declares `id: int`. By doing this, we are making a **contract** with the API clients, so that they can always expect the `id` to be there and to be an `int` (it will never be `None`).

/// tip