code: def run(self):
      if self.args.value is None and not self.args.unset:
          from dvc.config import ConfigError
  
          if self.args.level:
              conf = self.config.read(level=self.args.level)
          else:
              # Use merged config with default values
              conf = self.config
          try:
              self._check(conf, False, "cache", "dir")
              path = conf["cache"]["dir"]
          except ConfigError:
              if not self.config.dvc_dir or self.args.level:
                  raise
              path = os.path.join(self.config.dvc_dir, "cache")
          ui.write(path)
          return 0
      with self.config.edit(level=self.args.level) as conf:
          if self.args.unset:
              self._check(conf, False, "cache", "dir")
              del conf["cache"]["dir"]
          else:
              self._check(conf, False, "cache")
              conf["cache"]["dir"] = self.args.value
      return 0
  
file_path: dvc/dvc/commands/cache.py
imports: import argparse
  import os
  from dvc.cli import completion, formatter
  from dvc.cli.command import CmdBase
  from dvc.cli.utils import append_doc_link
  from dvc.commands.config import CmdConfig
  from dvc.ui import ui
label_desc: Use image node_id 1 for calling the CmdCacheDir obj's underlying member method code with example usage: obj.run() and returns: int, int