CloseAllPositions: parse error: expected string near offset 30 of '200'

[harrysun0]

Everytime I use CloseAllPositions function, there is always an error "parse error: expected string near offset 30 of '200'"

for example

func (c *Common) CloseAllPositions() error {
    _, err := c.TradeClient.CloseAllPositions(alpaca.CloseAllPositionsRequest{
        CancelOrders: true,
    })

    return err
}

it seems this error occurs when unmarshaling response body

// CloseAllPositions liquidates all open positions at market price.
func (c *Client) CloseAllPositions(req CloseAllPositionsRequest) ([]Order, error) {
    u, err := url.Parse(fmt.Sprintf("%s/%s/positions", c.opts.BaseURL, apiVersion))
    if err != nil {
        return nil, err
    }

    q := u.Query()
    q.Set("cancel_orders", strconv.FormatBool(req.CancelOrders))
    u.RawQuery = q.Encode()

    resp, err := c.delete(u)
    if err != nil {
        return nil, err
    }

    var orders orderSlice
    if err = unmarshal(resp, &orders); err != nil {
        return nil, err
    }
    return orders, nil
}