code: def execute(cur, sql):
      
      command, verbose, arg = parse_special_command(sql)
  
      if (command not in COMMANDS) and (command.lower() not in COMMANDS):
          raise CommandNotFound
  
      try:
          special_cmd = COMMANDS[command]
      except KeyError:
          special_cmd = COMMANDS[command.lower()]
          if special_cmd.case_sensitive:
              raise CommandNotFound('Command not found: %s' % command)
  
      # "help <SQL KEYWORD> is a special case.
      if command == 'help' and arg:
          return show_keyword_help(cur=cur, arg=arg)
  
      if special_cmd.arg_type == NO_QUERY:
          return special_cmd.handler()
      elif special_cmd.arg_type == PARSED_QUERY:
          return special_cmd.handler(cur=cur, arg=arg, verbose=verbose)
      elif special_cmd.arg_type == RAW_QUERY:
          return special_cmd.handler(cur=cur, query=sql)
docs: Execute a special command and return the results. If the special command
      is not supported a KeyError will be raised.