This event is fired when a player stops using a bow.

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

Event interface extensions

Link to event-interface-extensions

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

ZenGetters/ZenSetters

Link to zengetterszensetters

The following information can be retrieved/set during the event:

ZenGetterZenSetterType
ZenGetter
bow
ZenSetter
Type
IItemStack
ZenGetter
charge
ZenSetter
charge
Type
int
ZenGetter
world
ZenSetter
Type
String
ZenGetter
player
ZenSetter
Type
IPlayer