code: def _list(self):
      if any((self.args.name, self.args.value, self.args.unset)):
          logger.error(
              "-l/--list can't be used together with any of these "
              "options: -u/--unset, name, value"
          )
          return 1
  
      levels = self._get_appropriate_levels(self.args.level)
  
      for level in levels:
          conf = self.config.read(level)
          prefix = self._config_file_prefix(
              self.args.show_origin, self.config, level
          )
          configs = list(self._format_config(conf, prefix))
          if configs:
              ui.write("\n".join(configs))
  
      return 0
  
imports: import argparse
  import os
  from funcy import set_in
  from dvc.cli import formatter
  from dvc.cli.command import CmdBaseNoRepo
  from dvc.cli.utils import append_doc_link
  from dvc.log import logger
  from dvc.ui import ui
label_desc: Use image node_id 3 for calling the CmdConfig obj's underlying member method code with example usage: obj._list() and returns: int, int