code: def warning(self, message, print_location=True):
          
          msg = "Warning"
          if print_location and (exshared.location != None):
              wline = lineno(exshared.location, exshared.text)
              wcol = col(exshared.location, exshared.text)
              wtext = line(exshared.location, exshared.text)
              msg += " at line %d, col %d" % (wline, wcol)
          msg += ": %s" % message
          if print_location and (exshared.location != None):
              msg += "\n%s" % wtext
          print(msg)
docs: Displays warning message. Uses exshared for current location of parsing