Allow custom properties for each iteration?

[vicary]

Thanks for creating this, the API is simple and easy to understand.

I want to add memory footprints into benchmarks on top of ops/sec,

1. Is there a way to tap into each iteration and add memory stats into results?
2. Is there a way to keep the defaultCycle() pretty print, and add my own line for memory (peek, mean, median... etc.) after each cycle?