Creates an AVL tree.
Creates an AVL tree.
compare is an optional compare function for two values of
type T. If missing or null, T must extend Comparable and
the tree compares two values v1 and v2 using Ts
compareTo function.
If withEquivalenceClasses is true, the tree stores multiple values
which are equal with respect to compare but not identical with
respect to Darts identical()-function. In this case a tree node
become multi-valued.