return (Spliterator<T>) iterable.spliterator();
    }

    @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()

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

          // 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;

        return method.invoke(obj, args);
    }

    /**
     * Tests for the TreeConnectResponse interface using a mock implementation
     */
    @Nested
    @DisplayName("Interface Contract Tests")
    class InterfaceTests {

        private TreeConnectResponse mockResponse;

        @BeforeEach
        void setUp() {
            mockResponse = mock(TreeConnectResponse.class);
        }

to be bound by the terms and conditions of this Creative Commons
Attribution 4.0 International Public License ("Public License"). To the
extent this Public License may be interpreted as a contract, You are
granted the Licensed Rights in consideration of Your acceptance of
these terms and conditions, and the Licensor grants You such rights in
consideration of benefits the Licensor receives from making the

  private final double min;
  private final double max;

  /**
   * Internal constructor. Users should use {@link #of} or {@link StatsAccumulator#snapshot}.
   *
   * <p>To ensure that the created instance obeys its contract, the parameters should satisfy the
   * following constraints. This is the callers responsibility and is not enforced here.
   *
   * <ul>

        // 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;

        service.startAsync();
      } catch (IllegalStateException e) {
        // This can happen if the service has already been started or stopped (e.g. by another
        // service or listener). Our contract says it is safe to call this method if
        // all services were NEW when it was called, and this has already been verified above, so we
        // don't propagate the exception.

    Object[] copyTo = new Object[size];
    arraycopy(queue, 0, copyTo, 0, size);
    return copyTo;
  }

  /**
   * Returns the comparator used to order the elements in this queue. Obeys the general contract of
   * {@link PriorityQueue#comparator}, but returns {@link Ordering#natural} instead of {@code null}
   * to indicate natural ordering.
   */
  public Comparator<? super E> comparator() {
    return minHeap.ordering;