/*.................................................................................................................*/
 public TreeVector getCurrentBlock(Taxa taxa) {
   if (fillerTask instanceof Incrementable)
     ((Incrementable) fillerTask).setCurrent(currentTreeBlockIndex);
   setPreferredTaxa(taxa);
   TreeVector treeList = new TreeVector(taxa);
   fillerTask.fillTreeBlock(treeList, numTrees);
   return treeList;
 }