Numbering Messages in Enterprise Architect Communication Diagrams

I'm using Enterprise Architect (sparxsystems) to create a UML 2.0 Communication Diagram. I want the numbering of messages to be similar to this example: http://www.sparxsystems.com.au/uml_tool_guide/uml_dictionary/communicationdiagram.html.

How do I get messages to start with 2, 3, etc? Whenever I create a new message it creates it as 1.x. 开发者_C百科I see how to re-order messages, but not how to start a new sequence.

The example mentions that "a new number segment begins for a new layer of processing", but does not mention how to define a new layer of processing.

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Figured it out.

Right-click on the message. Select Collaboration Properties.

Check the box next to Start New Group.

Click OK.