The pull tester entry point can be found here:

https://github.com/bitcoinj/bitcoinj/blob/master/core/src/test/java/com/google/bitcoin/core/BitcoindComparisonTool.java

(nb: in the near future I will be re-namespacing the library from com.google.bitcoin to org.bitcoinj to reflect that it no longer has anything to do with Google and then this link will break).

The code itself is a rather bad example of copy/paste coding and I can say that, because Matt knows it and already plans to refactor things ;) So if anyone is thinking of adding tests to the framework coordinate with him first to ensure you don't end up conflicting with a big refactor/rewrite.