The while syntax allows to add labels on all edges except on the upward one.
For example, in the following loop, I didn't find a way to add a label to the edge going from "task" to "test" :
while (test) is (value1)
A possible extension would be:
while (test) is (value1) loop (value3)
adding a label "value3" to the edge going back from "task" up to "test".
Please provide a way to add a label on upward edge of while loops.