Now, one tiny thing that we need to do to help us understand how the chainIsValid method works is to log out the previousBlockHash and the currentBlock hash of every single block so that we can compare them ourselves. Consequently, in the chainIsValid method inside of the for loop, let's add the following lines of code before the loop ends:
console.log('previousBlockHash =>', prevBlock [ 'hash']);console.log('currentBlockHash =>', currentBlock [ 'hash']);
Let's save this modification and run the test again. This time, when we run the test, we should see all of the hashes logged out so that we can compare them for ourselves and see what's really happening inside of this method. After running ...
