Sender interface updated, Iterable<Event> getEvents() added
EventManager javadocs updated
EventManager -> Iterable<Event> getEvents() added
EventManager version updated
Concurrency package javadocs updated
TreeNode added
TreeNode main methods implemented
TreeNode -> toString() added
TreeNode javadocs updated
TreeNode error handling added
TreeNode -> getChildren() modified
NotEffectiveKey added
IllegalKey added
Key annotations applied
NotEffectiveKey renamed to IllegalKey, javadocs updated
Minor code refactorings
Pair added
TreeNode<E extends Serializable> reworked to TreeNode<E>
ImmutablePair added
MutablePair added