Set the presentation for UML2 Lifeline
You can set the property represents for lifelines.
Procedure. Procedure
Right-click a lifeline.
Click Set 'represents' property. The Select elements dialog opens.
Search for the UML2 element to which you want to connect the lifeline.
Select the required UML2 element.
Click OK.
The selected lifeline is connected to the relevant UML2 element type.