I was trying to modify the REST.DocServer sample in the SAMPLE namespaces to use the new %Object and %Array system objects (Ensemble 2016.2 build 636) with the following changes:
/// This method returns a list of namespaces for this server
ClassMethod GetNamespaces() As %Status
{
#dim tSC As %Status = $$$OK
#dim tList,tNS,tFilteredList,tValue As %String
#; Get the list of namespaces
Do List^%SYS.NAMESPACE(.tList)
Set tNS="" For {
Set tNS=$Order(tList(tNS),1,tValue) If tNS="" Quit