Nothing much
Iterate through pairs (key, value)
Iterate through pairs (key, value)
Introduce an empty tree :) to simplify initialization
Remove a few asInstanceOf
Generate four random  centroids
Nothing much
Implement both of norm() and sqr() methods
Compute full energy for all of the subtrees

A sum of energies of subtrees plus their mutual energy assigned to
energy of their parent node
Calculate something dispersion-like
Colorify cluster by means of energy estimation
Implement a tool to discern clusters
Consider distance as a deflection from average

In this case dispersion is a sum of squares of distances from
hypothetical average vector that should be the case if it's a cluster,
that should be truth by construction of algorithm.
Make types more convenient.
Rectify types
Test clustering on chains

(A lot of test code still exists)
Test clustering a simple cloud

.. passed