Method IsJust

test-app/runtime/src/main/cpp/include/v8-maybe.h:32–32

 public:
  V8_INLINE bool IsNothing() const { return !has_value_; }
  V8_INLINE bool IsJust() const { return has_value_; }

  /**
   * An alias for |FromJust|. Will crash if the Maybe<> is nothing.