lambda to add stereotype

to be able to create nicer "null" nodes.

@startuml
scale 1.0

skinparam object {
  BackgroundColor<<null>> white
  BorderColor<<null>> white
  StereotypeFontColor<<null>> white
}


object "A" as node0 #4C78A6 {
}
object "B" as node1 #A78344 {
}
object "null" as node9<<null>> {
}

node0 *-- node1 : L
node0 *-- node9 : U

@enduml