new UnhashableObject(5));
    }
  }

  public static class Colliders extends SampleElements<Object> {
    public Colliders() {
      super(new Collider(1), new Collider(2), new Collider(3), new Collider(4), new Collider(5));
    }
  }

  private static final class Collider {
    final int value;

    Collider(int value) {
      this.value = value;
    }

    @Override

          new UnhashableObject(5));
    }
  }

  public static class Colliders extends SampleElements<Object> {
    public Colliders() {
      super(new Collider(1), new Collider(2), new Collider(3), new Collider(4), new Collider(5));
    }
  }

  private static final class Collider {
    final int value;

    Collider(int value) {
      this.value = value;
    }

    @Override

    assertEqualHashCode(Predicates.or(p1, p2), Predicates.or(p1, p2));

    // While not a contractual requirement, we'd like the hash codes for ands
    // & ors of the same predicates to not collide.
    assertTrue(Predicates.and(p1, p2).hashCode() != Predicates.or(p1, p2).hashCode());
  }

  @J2ktIncompatible
  @GwtIncompatible // reflection
  public void testNulls() throws Exception {