RFC: Arbitrary frame around a section of the diagram

[MrCoder]

This was asked for by a user from Coles.

Is there a way to do box around a section of sequence diagram in ZenUML? Similar to Par or Opt but with an arbitrary name? For example to outline the area of interest.

DSL

To represent a arbitrary frame the following syntax should be used:

1. critical {} or critical(ID) {}. Note "Critical Region" is a concept from the UML Spec
2. frame {} or frame(ID) {}
3. section {} or section(ID) {}

Rendering

If ID is not provided

If ID is provided