This class implements a partitioned fuzzy node tree; the fuzzy node trees are partitioned into buckets where each bucket corresponds to the KEYSUm of the fuzzy node root. * The rationality behind
this tree is to split up a fuzzy node into a tree consisting of several fuzzy node roots based on the key sum of the fuzzy node. * This helps to restrict the number of fuzzy nodes searched to a
boundary around the key sum of a search fuzzy key.