Class test.Dyn Extends %Persistent
{

Property json As %DynamicObject;

/// do ##class(test.Dyn).test()
ClassMethod test()
{
  do ..%KillExtent()
  for len = 100, $$$MaxStringLength - 1, $$$MaxStringLength, $$$MaxStringLength+1, $$$MaxStringLength *2 {
    set sc = ..save(len)
    write "Len: ",len, " Result: ",$case($$$ISERR(sc), $$$YES: $System.Status.GetErrorText(sc), : "OK"),!
  }
}

ClassMethod save(len)
{
  set json = {}
  set stream = ..getStream(len-8) // -8 because {"a":""}
  do json.%Set("a", stream, "stream")
 
  set obj = ..%New()
  set obj.json = json
  quit obj.%Save()
}

ClassMethod getStream(len)
{
  set stream = ##class(%Stream.TmpCharacter).%New()
 
  if len<$$$MaxStringLength {
    do stream.Write($tr($j("",len)," ","A"))
  } else {
    for i=1:$$$MaxStringLength:len {
      do stream.Write($tr($j("",$$$MaxStringLength)," ","A"))
    }
    do stream.Write($tr($j("",len-i)," ","A"))
  }
  quit stream
}
}