Hello U.,
Here is an example of procedure, as:
@startuml
!procedure $tree($d, $max, $min)
class "Tree" as tree-$d-$max-$min {
Depth: $d
--
MaxValue: $max
--
MinValue: $min
}
!endprocedure
$tree(1,2,3)
$tree(10,5,6)
@enduml
If that can help,
Regards,
Th.