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.

import org.codelibs.fess.crawler.entity.ResponseData;
import org.codelibs.fess.crawler.processor.ResponseProcessor;
import org.dbflute.utflute.core.PlainTestCase;

/**
 * Test class for RuleManager interface.
 * Tests the contract and behavior of RuleManager implementations.
 */
public class RuleManagerTest extends PlainTestCase {

    /**
     * Test implementation of RuleManager for testing purposes
     */

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

      return Iterators.unmodifiableIterator(iterable.iterator());
    }

    @Override
    public String toString() {
      return iterable.toString();
    }
    // no equals and hashCode; it would break the contract!
  }

  /** Returns the number of elements in {@code iterable}. */
  public static int size(Iterable<?> iterable) {
    return (iterable instanceof Collection)
        ? ((Collection<?>) iterable).size()

 * elements, if there is no comparator) to test element equality. As a result, if the comparator is
 * not consistent with equals, some of the standard implementations may violate the {@code Map}
 * contract.
 *
 * <p>The {@code standard} methods and the collection views they return are not guaranteed to be
 * thread-safe, even when all of the methods that they depend on are thread-safe.
 *
 * @author Louis Wasserman

 * elements, if there is no comparator) to test element equality. As a result, if the comparator is
 * not consistent with equals, some of the standard implementations may violate the {@code Map}
 * contract.
 *
 * <p>The {@code standard} methods and the collection views they return are not guaranteed to be
 * thread-safe, even when all of the methods that they depend on are thread-safe.
 *
 * @author Louis Wasserman

import org.codelibs.fess.crawler.entity.ResponseData;
import org.codelibs.fess.crawler.processor.ResponseProcessor;
import org.dbflute.utflute.core.PlainTestCase;

/**
 * Test class for Rule interface.
 * Tests the contract and behavior of Rule implementations.
 */
public class RuleTest extends PlainTestCase {

    /**
     * Test implementation of Rule interface for testing purposes
     */

          // Checking subtype between declared and actual type bounds
          // adds recursive isSubtypeOf() call and feels complicated.
          // There is no contract one way or another as long as isSubtypeOf() works as expected.
          combined.addAll(asList(typeParam.getBounds()));
          if (combined.size() > 1) { // Object is implicit and only useful if it's the only bound.

        // This cast is not itself safe, but the following statement
        // will fail if the runtime type of items[i] is not assignable
        // to the runtime type of a[k++], which is all that the method
        // contract requires (see @throws ArrayStoreException above).
        @SuppressWarnings("unchecked")
        T t = (T) items[i];
        a[k++] = t;
        i = inc(i);
      }
      if (a.length > count) a[count] = null;