120c120,121
< dot_add_edge(simNode, callgraph, full_port_name, port)
---
> if port.peer:
> dot_add_edge(simNode, callgraph, full_port_name, port)
123c124,125
< dot_add_edge(simNode, callgraph, full_port_name, p)
---
> if p.peer:
> dot_add_edge(simNode, callgraph, full_port_name, p)