@Override public void modifyVariableId(String nodeId,String newId){
  Map<Assignment,UtilityEstimate> utilities2=new HashMap<Assignment,UtilityEstimate>();
  for (  Assignment a : table.keySet()) {
    Assignment b=new Assignment();
    for (    String var : a.getVariables()) {
      String newVar=(var.equals(nodeId)) ? newId : var;
      b.addPair(newVar,a.getValue(var));
    }
    utilities2.put(b,table.get(a));
  }
  table=utilities2;
}

@ Override public void modifyVariableId ( String nodeId , String newId ) { Map < Assignment , UtilityEstimate > utilities2 = new HashMap < Assignment , UtilityEstimate > ( ) ; for ( Assignment a : table . keySet ( ) ) { Assignment b = new Assignment ( ) ; for ( String var : a . getVariables ( ) ) { String newVar = ( var . equals ( nodeId ) ) ? newId : var ; b . addPair ( newVar , a . getValue ( var ) ) ; } utilities2 . put ( b , table . get ( a ) ) ; } table = utilities2 ; }
modifies a variable label with a new one
