code: func (c *Client) KeyList(lr *ListRange) ([]Key, error) {
  	req, err := c.NewRequest("GET", "/account/keys", nil, nil)
  	if err != nil {
  		return nil, err
  	}
  
  	if lr != nil {
  		lr.SetHeader(req)
  	}
  
  	var keysRes []Key
  	return keysRes, c.DoReq(req, &keysRes)
  }
docs: // List existing keys.
  //
  // lr is an optional ListRange that sets the Range options for the paginated
  // list of results.