CHILD: Topology/IPClassA
  CHILD: Topology/IPClassA/Device
  CHILD: Topology/IPClassA/Device/log_ratio
  CHILD: Topology/IPClassA/Device/poll_interval
  CHILD: Topology/IPClassA/Device = 2
  CHILD: Topology/IPClassA/Device = 2/poll_interval
  CHILD: Topology/IPClassA/Device = 2/is_managed
  CHILD: Topology/IPClassA/Device = 2/Port
  CHILD: Topology/IPClassA/Device = 2/Port/ifPhysAddress
  CHILD: Topology/IPClassA/Device = 2/Port/poll_interval
  CHILD: Topology/IPClassC
  CHILD: Topology/IPClassC/Device
  CHILD: Topology/IPClassC/Device/poll_interval
  CHILD: Location 


##</code><code>##

  CHILD: Topology/IPClassA/Device/log_ratio
  CHILD: Topology/IPClassA/Device/poll_interval
  CHILD: Topology/IPClassA/Device = 2/poll_interval
  CHILD: Topology/IPClassA/Device = 2/is_managed
  CHILD: Topology/IPClassA/Device = 2/Port
  CHILD: Topology/IPClassA/Device = 2/Port/ifPhysAddress
  CHILD: Topology/IPClassA/Device = 2/Port/poll_interval
  CHILD: Topology/IPClassC/Device/poll_interval
  CHILD: Location


##</code><code>##

  push (@foo, $_) unless ($seen{$_}++);