code: def _InsservExpander(self, facilities, val):
      
      expanded = []
      if val.startswith("$"):
        vals = facilities.get(val, [])
        for v in vals:
          expanded.extend(self._InsservExpander(facilities, v))
      elif val.startswith("+"):
        expanded.append(val[1:])
      else:
        expanded.append(val)
      return expanded
docs: Expand insserv variables.