I see how that would clean up the vCard extraction, however, we need the i value also to get the associated etag value from the parallel etag array. I looked up in the docs to see if there was a parallel generator type for..in, but it doesn't look like there is. Here's the docs: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for...in 

Can you think of anything?