Cosmos Dev Series: Cosmos-SDK-based Blockchain Upgrade - NewSimApp x/gov handler

app.go

func NewSimApp(...) *SimApp {
    ...
    // register the proposal types
    govRouter := govtypes.NewRouter()
    govRouter.AddRoute(govtypes.RouterKey, govtypes.ProposalHandler).
        AddRoute(upgradetypes.RouterKey, upgrade.NewSoftwareUpgradeProposalHandler(app.UpgradeKeeper))
 
    govKeeper := govkeeper.NewKeeper(
        appCodec, keys[govtypes.StoreKey], app.GetSubspace(govtypes.ModuleName), app.AccountKeeper, app.BankKeeper,
        &stakingKeeper, govRouter,
    )
    ...
}