private synchronized PaStepStub getPaStepStub() {
if (paStepStub != null) return paStepStub;
Stereotype stereotype = edge.getApplicableStereotype(PaStepDecorator.QUALIFIED_NAME);
PaStepDecorator decorator = null;
try {
decorator = (PaStepDecorator) getFactory().getDecorator(stereotype);
} catch (ClassNotFoundException e) {} // cannot happen
catch (InvalidContextException e) {} // cannot happen
return (PaStepStub) decorator.getStub(edge);
}