volume.go
func (c *Client) RestoreSnapshot(dcid string, volid string, snapshotID string) (*http.Header, error) {
	path := volumePath(dcid, volid) + "/restore-snapshot"
	data := url.Values{}
	data.Set("snapshotId", snapshotID)
	ret := &http.Header{}
	err := c.client.Post(path, data, ret, http.StatusAccepted)
	return ret, err
}
func (c *Client) RestoreSnapshot(dcid string, volid string, snapshotID string) (*http.Header, error) {
	path := volumePath(dcid, volid) + "/restore-snapshot"
	data := url.Values{}
	data.Set("snapshotId", snapshotID)
	ret := &http.Header{}
	err := c.client.Post(path, data, ret, http.StatusAccepted)
	return ret, err
}
// RestoreSnapshot restores a volume with provided snapshot