volume.go
func (c *Client) GetVolume(dcid string, volumeID string) (*Volume, error) {
	url := volumePath(dcid, volumeID) + `?depth=` + c.client.depth
	ret := &Volume{}
	err := c.client.Get(url, ret, http.StatusOK)
	return ret, err
}
func (c *Client) GetVolume(dcid string, volumeID string) (*Volume, error) {
	url := volumePath(dcid, volumeID) + `?depth=` + c.client.depth
	ret := &Volume{}
	err := c.client.Get(url, ret, http.StatusOK)
	return ret, err
}
//GetVolume gets a volume