class Information {
String sName
String birthday
String age
}

class Directory {
String name
String address
contains Information xInfo
}

public static val aDirs = new ArrayList<Directory>
public static val aInfo = new ArrayList<Information>

def public setInfo()
{
   for (m: aDirs)
   {
       val x = aInfo.findFirst[m.name.equals(SName)]
       if (x != null)
           m.xInfo = x //print also shows that this is correctly set.
   }
}

def public printInfo()
{
  for (m: aDirs)
  {
    if (m.xInfo == null) // ERROR: m.xInfo is null again!
    {
      // do nothing
    }
  }
}

class Directory {
String name
String address
derived Information xInfo get {
 MySingleton::instance.getInfo(name)
}
}