question: public void rebuild ( ) { final Collection < T > toReadd = getAll ( ) ; root . cuttoffDistance = - 1 ; root . far = null ; root . close = null ; root . coordinate = null ; root . value = null ; root . recomputeSize ( ) ; add ( toReadd ) ; }
target:  rebuilds the full tree. Might help to rebalance a tree imbalanced by removals, or make a tree with lots of invalidated values smaller.