it('should not allow forging with the same parent multiple times', async () => {
      const forgerTokenId = FORGER_TOKEN_ID;
      const mergerTokenId = MERGER_TOKEN_ID;
      const fee = FORGING_FEE;

      await entityForging.connect(owner).listForForging(forgerTokenId, fee);

      const forgerEntropy = await nft.getTokenEntropy(forgerTokenId);
      const mergerEntrypy = await nft.getTokenEntropy(mergerTokenId);
      
      /// The new token id will be forger token id + 1, cause it's the last item
      const expectedTokenId = FORGER_TOKEN_ID + 1;
      await expect(
        entityForging
          .connect(user1)
          .forgeWithListed(forgerTokenId, mergerTokenId, {
            value: FORGING_FEE,
          })
      )
        .to.emit(entityForging, 'EntityForged')
        .withArgs(
          expectedTokenId,
          forgerTokenId,
          mergerTokenId,
          (forgerEntropy + mergerEntrypy) / 2n,
          FORGING_FEE
        )
        .to.emit(nft, 'NewEntityMinted')
        .withArgs(
          await user1.getAddress(),
          expectedTokenId,
          2,
          (forgerEntropy + mergerEntrypy) / 2n
        );

        // List it again
        await entityForging.connect(owner).listForForging(forgerTokenId, fee);
        const expectedId = FORGER_TOKEN_ID + 2;

        // Forge again with the same parent
        await expect(
          entityForging
            .connect(user1)
            .forgeWithListed(forgerTokenId, mergerTokenId, {
              value: FORGING_FEE,
            })
        )
          .to.emit(entityForging, 'EntityForged')
          .withArgs(
            expectedId,
            forgerTokenId,
            mergerTokenId,
            (forgerEntropy + mergerEntrypy) / 2n,
            FORGING_FEE
          )
          .to.emit(nft, 'NewEntityMinted')
          .withArgs(
            await user1.getAddress(),
            expectedId,
            2,
            (forgerEntropy + mergerEntrypy) / 2n
          );
    });
