code: def _remote_file_exists(self, path):
          
          LOG.debug('_remote_file_exists(%r)', path)
          return self._connection.get_chain().call(
              ansible_mitogen.target.file_exists,
              mitogen.utils.cast(path)
          )
docs: Determine if `path` exists by directly invoking os.path.exists() in the
          target user account.