add test: delete many expired batches

[significance]

      // todo add this and perhaps other, longer tests
      // it('should delete many expired batches', async function () {
      //   const price = 2048;
      //   await setPrice(price);

      //   transferAmount = 2000 * batch.initialPaymentPerChunk * batchSize;
      //   expectedNormalisedBalance = batch.initialPaymentPerChunk;

      //   await token.mint(stamper, transferAmount);
      //   (await ethers.getContract('TestToken', stamper)).approve(postageStamp.address, transferAmount);

      //   for (let i = 0; i < 20; i++) {
      //     const nonce =
      //       '0x000000000000000000000000000000000000000000000000000000000000' + i.toString().padStart(4, '0');
      //     await postageStamp.createBatch(
      //       stamper,
      //       10240 - i,
      //       batch.depth,
      //       batch.bucketDepth,
      //       nonce,
      //       batch.immutable
      //     );
      //   }

      //   await mineNBlocks(5);

      //   const nonce3 = '0x0000000000000000000000000000000000000000000000000000000000011237';
      //   await postageStamp.createBatch(
      //     stamper,
      //     4096,
      //     batch.depth,
      //     batch.bucketDepth,
      //     nonce3,
      //     batch.immutable
      //   );

      //   expect(await postageStamp.pot()).equal(210 * 2 ** batch.depth);
      // });

[agazso]

What is this test meant to test? There are a lot of implied logic going on, because the name states that it is about deleting expired batches but the matcher at the end tests for a certain amount of pot.

[significance]

What is this test meant to test? There are a lot of implied logic going on, because the name states that it is about deleting expired batches but the matcher at the end tests for a certain amount of pot.

yes, it was from the initial battery of tests that i replaced. i think all of the implied logic should be tested. this may already be the case, but let's check.