// defined in a caller's package
type RedfishClient interface {
    GetService() *Service
    Logout()
}

type MyType struct {
    client RedfishClient 
}

func NewMyType(endpoint string) (*MyType, error) {
    r := &MyType{}
    var err error
    r.client, err = gofish.ConnectDefault(endpoint)
    if err != nil {
        return nil, err
    }
    return r, nil
)

func main(){
    mt, _ := NewMyType("")
    fmt.Println(mt.client.GetService().Systems()[0].BIOSVersion)
    mt.client.Logout()
}