Private
constructorAdds a callback that will be called before an item is used.
This function can't be called in read-only mode.
This function can be called in early-execution mode.
Adds a callback that will be called before an item is used.
This function can't be called in read-only mode.
This function can be called in early-execution mode.
Removes a callback from being called before an item is used.
This function can't be called in read-only mode.
This function can be called in early-execution mode.
Manages callbacks that fire before an item is used.