Method ToString

tensorflow/compiler/jit/deadness_analysis.cc:216–218

      : Predicate(id), operands_({operand}) {}

  string ToString() const override {
    return absl::StrCat("~", operand()->ToString());
  }

  Kind kind() const override { return Kind::kNot; }
  Predicate* operand() const { return operands_[0]; }