docs: public static <T> Predicate<T> isEqual( final Object obj ) {
          if (obj == null) {
              return new Predicate<T>() {
                  @Override
                  public boolean test( T input ) {
                      return input == null;
                  }
              };
          }
          return new Predicate<T>() {
              @Override
              public boolean test( T input ) {
                  return Objects.equals(input, obj);
              }
          };
      }