code: def flush(bank, key=None):
      '''
      Remove the key from the cache bank with all the key content.
      '''
      _init_client()
      if key is None:
          etcd_key = '{0}/{1}'.format(path_prefix, bank)
      else:
          etcd_key = '{0}/{1}/{2}'.format(path_prefix, bank, key)
      try:
          client.read(etcd_key)
      except etcd.EtcdKeyNotFound:
          return  # nothing to flush
      try:
          client.delete(etcd_key, recursive=True)
      except Exception as exc:
          raise SaltCacheError(
              'There was an error removing the key, {0}: {1}'.format(
                  etcd_key, exc
              )
          f flush(bank, key=None):
      '''
      Remove the key from the cache bank with all the key content.
      '''
      _init_client()
      if key is None:
          etcd_key = '{0}/{1}'.format(path_prefix, bank)
      else:
          etcd_key = '{0}/{1}/{2}'.format(path_prefix, bank, key)
      try:
          client.read(etcd_key)
      except etcd.EtcdKeyNotFound:
          return  # nothing to flush
      try:
          client.delete(etcd_key, recursive=True)
      except Exception as exc:
          raise SaltCacheError(
              'There was an error removing the key, {0}: {1}'.format(
                  etcd_key, exc
              )
          )
docs: Remove the key from the cache bank with all the key content.