It would be nice to be able to do the following:
- while being into the code, select a class name and right-click to choose a menu entry like 'start a sequence diagram
session', then the class name is RE and put to create a first lifeline.
- each time a class name is selected, and right-clicked (through the selection of a specific entry menu), this class
goes through RE and a new associated lifeline is created 
- each time a method name is selected and right-clicked, a corresponding method call is associated with the last created
lifeline and the targeted lifeline will be the new class name to be right-clicked (or an empty lifeline is no class is
selected).
- the session ends while right-clicking and selecting the entry menu 'end sequence diagram session'

The goal is to create a sequence diagram just like navigating into the code.