Tests for geonames with k=1 and data size=2000 successfully pass
Tests for geonames with k=1 and data size=4000 successfully pass
Tests for geonames with k=1 and data size=8000 successfully pass
Tests for geonames with k=1 and data size=16000 successfully pass
Tests for geonames with k=1 and data size=10000 successfully pass
Tests for geonames with k=1 and data size=100000 successfully pass
Tests for geonames with k=1 and ALL data successfully pass

Type 2 group trees are NOT built in a binary tree structure,
since too much memory is used. Instead all light children
are merged into one node.

VM options to run the program
-ea -XX:+UseConcMarkSweepGC -Xmx6g

NOTE: Possibly less heap size is needed.