code: protected void clearClusters() {
          MP modelParameters = knowledgeBase.getModelParameters();
          Map<Integer, CL> clusterMap = modelParameters.getClusterMap();
          for(Map.Entry<Integer, CL> e : clusterMap.entrySet()) {
              Integer clusterId = e.getKey();
              CL c = e.getValue();
              c.clear();
              clusterMap.put(clusterId, c);
          }
      }
docs: Clears the clusters from their internal caching parameters before storing
  them. It should be called in the _fit() method of each Clusterer.