- Add :meth:`neighbors.NearestCentroid.decision_function`,
  :meth:`neighbors.NearestCentroid.predict_proba` and
  :meth:`neighbors.NearestCentroid.predict_log_proba`
  to the :class:`neighbors.NearestCentroid` estimator class.
  Support the case when `X` is sparse and `shrinking_threshold`
  is not `None` in :class:`neighbors.NearestCentroid`.
  By :user:`Matthew Ning <NoPenguinsLand>`
