Invalidating a test

We can do so by calling the following function inside the TestCreator.sol smart contract:

    function invalidateTest(uint256 testId) external { ... }

Invalidating a certain test can only be done by the owner of the corresponding testId.

As a result of the invalidation, the test will no longer be solveable by anyone, which is represented on-chain by a testType = 255.

The test, and all its attributes will still be viewable on-chain. Similarly, the obtained credential NFTs will still live on chain, but their corresponding testType will show that they are now invalidated.