AddItem is an action which adds a single item with the specified title.

ClearCompleted is an action which clears the completed items.

DestroyItem is an action which destroys the item specified by the index.

ReplaceItems is an action that replaces all items with the specified ones.

SetAllCompleted is an action which marks all existing items as being completed or not.

SetCompleted is an action which specifies the completed state of an existing item.

SetFilter is an action which sets the filter for the viewed items.

SetTitle is an action which specifies the title of an existing item.