docs: def get_atomtrailer_list(r):
      """Capture only the leading dotted name list.
  
      A full sequence typically includes function calls and parameters.
      pkga.pkgb.pkgc.one_call(arg1, arg2, arg3=4)
  
      """
      dot_set = set()
      for n in r.find_all(("atomtrailers",)):
          name_list = []
          for x in n.value:
              if x.type != "name":
                  break
              name_list.append(x.value)
          if name_list:
              dot_set.add(tuple(name_list))
      return sorted(dot_set)