SameListInstance that = (SameListInstance) obj;
        return s == that.s;
      }
      return false;
    }
  }

  static class WithStreamParameter {
    private final List<?> list;

    // This should be ignored.
    public WithStreamParameter(Stream<?> s, String str) {
      this.list = s.collect(Collectors.toList());
      checkNotNull(str);
    }
  }