public void addChildren(List<Adm> children){
  if (children != null) {
    for (    Adm child : children) {
      addChild(child);
    }
  }
  ;
}

public void addChildren ( List < Adm > children ) { if ( children != null ) { for ( Adm child : children ) { addChild ( child ) ; } } ; }
do a double set : add ( not replace ! ) the children to the current adm and set the current adm as the parent of the specified children
