I want to create a two links. One is from class A and the other link shall be from class B. And
class be is derived from class A. I need to do so because the shape of the two connections shall be
different.
In class A I defined the link source and target as well. I can draw the class A link between two
nodes. Every thing is fine. But when I want to draw class B link it disappears from the diagram but
is save to the file. Once I open the diagram again both links are visible but both have the shape of
class A.