code: func (c *Client) Delete(key string) error {
  	cn, err := c.sendCommand(key, cmdDelete, nil, 0, nil)
  	if err != nil {
  		return err
  	}
  	_, _, _, _, err = c.parseResponse(key, cn)
  	c.condRelease(cn, &err)
  	return err
  }
docs: // Delete deletes the item with the provided key. The error ErrCacheMiss is
  // returned if the item didn't already exist in the cache.