Determine if the callbacks have already been called at least once.

Lock a callback list in its current state. This method returns the Callbacks object onto which it

Disable a callback list from doing anything more. This method returns the Callbacks object onto

Call all callbacks in a list with the given context and arguments. This method returns the Callbacks

Remove all of the callbacks from a list. This method returns the Callbacks object onto which it

Remove a callback or a collection of callbacks from a callback list. This method returns the Callbacks

Determine if the callbacks list has been disabled.

Determine if the callbacks list has been locked.

Determine whether or not the list has any callbacks attached. If a callback is provided as an argument, determine whether it is in a list.

Add a callback or a collection of callbacks to a callback list. This method returns the Callbacks