code: def p_statement_call(p):
      
      if len(p) > 2 and p[2] is None:
          p[0] = None
      elif len(p) == 2:
          entry = SYMBOL_TABLE.get_entry(p[1])
          if not entry or entry.class_ in (CLASS.label, CLASS.unknown):
              p[0] = make_label(p[1], p.lineno(1))
          else:
              p[0] = make_sub_call(p[1], p.lineno(1), make_arg_list(None))
      else:
          p[0] = make_sub_call(p[1], p.lineno(1), p[2])
docs: statement : ID arg_list
                    | ID arguments
                    | ID