public @NotNull RelationType getNegated() {
    return switch (this) {
      case LE -> GT;
      case LT -> GE;
      case GE -> LT;
      case GT -> LE;
      case EQ -> NE;
      case NE -> EQ;
      case IS -> IS_NOT;
      case IS_NOT -> IS;
    };
  }
public @NotNull RelationType getNegated()