private void drainSinks()
{
//drain sinks
if (addItemsSink.Count > 0)
{
foreach (object o in addItemsSink)
{
this.addObject(o);
}
addItemsSink.Clear();
}
if (removeItemsSink.Count > 0)
{
foreach (object o in removeItemsSink)
{
this.removeObject(o);
}
removeItemsSink.Clear();
}
}