private void problemEdgePrep(){
  for (int i=0; i < numTreeRoots; i++) {
    AbstractBURS_TreeNode n=treeRoots[i];
    problemEdgePrep(n,n.dg_node);
  }
}

private void problemEdgePrep ( ) { for ( int i = 0 ; i < numTreeRoots ; i ++ ) { AbstractBURS_TreeNode n = treeRoots [ i ] ; problemEdgePrep ( n , n . dg_node ) ; } }
stage 1b : do bookkeeping to make it easier to identify harmless problem edges .
