The BlockBreak Event is fired whenever a block is being broken.
You can cancel the event to prevent the block from being broken.

You will need to cast the event in the function header as this class:
crafttweaker.event.BlockBreakEvent
You can, of course, also import the class before and use that name then.

BlockBreak Events implement the following interfaces and are able to call all of their methods/getters/setters as well:

• IEventCancelable
• IBlockEvent

The following information can be retrieved from the event:

ZenGetter	ZenSetter	Type
ZenGetter player	ZenSetter ​	Type IPlayer
ZenGetter isPlayer	ZenSetter ​	Type bool
ZenGetter experience	ZenSetter experience	Type int