return "Predicates.alwaysTrue()";
      }
    },
    /** @see Predicates#alwaysFalse() */
    ALWAYS_FALSE {
      @Override
      public boolean apply(@CheckForNull Object o) {
        return false;
      }

      @Override
      public String toString() {
        return "Predicates.alwaysFalse()";
      }
    },
    /** @see Predicates#isNull() */
    IS_NULL {
      @Override

        return "Predicates.alwaysTrue()";
      }
    },
    /** @see Predicates#alwaysFalse() */
    ALWAYS_FALSE {
      @Override
      public boolean apply(@CheckForNull Object o) {
        return false;
      }

      @Override
      public String toString() {
        return "Predicates.alwaysFalse()";
      }
    },
    /** @see Predicates#isNull() */
    IS_NULL {
      @Override