The AE2 has in the contract that the item field in an IAEItemDefinition can be null due to the fact, if a special item is deactivated. This needs to be checked.
The base code was enhanced through Javadoc and split in responsibilities
The new update contained a split of the IEnergyHandler into the IEnergyReceiver and IEnergyProvider.
Since all tiles in AE2 are basically IEnergyReceivers we use them and changed the detection of opposing tile entities from IEnergyHandler to IEnergyReceiver
To integrate these into the current system, some changes to the background had to be done, especially to the feature handler. It now uses an interface to work against which you can implement to get your own feature handler instead modifying the base one and add several special cases code
thatsIch