设置关键级别的认可政策

Question

无法弄清楚如何使用关键级别的认可。

type Car struct {
    Make   string `json:"make"`
    Model  string `json:"model"`
    Colour string `json:"colour"`
    Owner  string `json:"owner"`
} 
APIstub.SetStateValidationParameter("make", []byte("Org2MSP.peer,Org1MSP.peer"))

I want to override the endorsement policy set on my channel.