add community multi-spend proposal (#915)

* feat: add community multi-spend proposal type

* feat: add handler for community multi-spend proposals

* chore: register new community multi-spend proposal

* feat: define client for community multi-spend proposal

* fix typos in example cli json

* fix: register now proposal type with module codec

* fix: register community multi-spend proposal with gov router, not committee

* fix: define kavadist keeper before referencing it

* nit: include deposit in example proposal

* nit: update comment

* nit: fix error codes

* nit: update comments

app/app.go

@@ -68,7 +68,7 @@ var (
 		distr.AppModuleBasic{},
 		gov.NewAppModuleBasic(
 			paramsclient.ProposalHandler, distr.ProposalHandler, committee.ProposalHandler,
-			upgradeclient.ProposalHandler,
+			upgradeclient.ProposalHandler, kavadist.ProposalHandler,
 		),
 		params.AppModuleBasic{},
 		crisis.AppModuleBasic{},
@@ -300,6 +300,14 @@ func NewApp(logger log.Logger, db dbm.DB, traceStore io.Writer, appOpts AppOptio
 		committeeGovRouter,
 		app.paramsKeeper,
 	)
+	app.kavadistKeeper = kavadist.NewKeeper(
+		app.cdc,
+		keys[kavadist.StoreKey],
+		kavadistSubspace,
+		app.supplyKeeper,
+		app.distrKeeper,
+		app.ModuleAccountAddrs(),
+	)
 
 	// create gov keeper with router
 	govRouter := gov.NewRouter()
@@ -308,7 +316,8 @@ func NewApp(logger log.Logger, db dbm.DB, traceStore io.Writer, appOpts AppOptio
 		AddRoute(params.RouterKey, params.NewParamChangeProposalHandler(app.paramsKeeper)).
 		AddRoute(distr.RouterKey, distr.NewCommunityPoolSpendProposalHandler(app.distrKeeper)).
 		AddRoute(upgrade.RouterKey, upgrade.NewSoftwareUpgradeProposalHandler(app.upgradeKeeper)).
-		AddRoute(committee.RouterKey, committee.NewProposalHandler(app.committeeKeeper))
+		AddRoute(committee.RouterKey, committee.NewProposalHandler(app.committeeKeeper)).
+		AddRoute(kavadist.RouterKey, kavadist.NewCommunityPoolMultiSpendProposalHandler(app.kavadistKeeper))
 	app.govKeeper = gov.NewKeeper(
 		app.cdc,
 		keys[gov.StoreKey],
@@ -365,12 +374,6 @@ func NewApp(logger log.Logger, db dbm.DB, traceStore io.Writer, appOpts AppOptio
 		app.pricefeedKeeper,
 		app.auctionKeeper,
 	)
-	app.kavadistKeeper = kavadist.NewKeeper(
-		app.cdc,
-		keys[kavadist.StoreKey],
-		kavadistSubspace,
-		app.supplyKeeper,
-	)
 	app.incentiveKeeper = incentive.NewKeeper(
 		app.cdc,
 		keys[incentive.StoreKey],

x/kavadist/alias.go

@@ -1,56 +1,69 @@
+// nolint
+// autogenerated code using github.com/rigelrozanski/multitool
+// aliases generated for the following subdirectories:
+// ALIASGEN: github.com/kava-labs/kava/x/kavadist/types
+// ALIASGEN: github.com/kava-labs/kava/x/kavadist/keeper
+// ALIASGEN: github.com/kava-labs/kava/x/kavadist/client
 package kavadist
 
-// DO NOT EDIT - generated by aliasgen tool (github.com/rhuairahrighairidh/aliasgen)
-
 import (
+	"github.com/kava-labs/kava/x/kavadist/client"
 	"github.com/kava-labs/kava/x/kavadist/keeper"
 	"github.com/kava-labs/kava/x/kavadist/types"
 )
 
 const (
+	EventTypeKavaDist                   = types.EventTypeKavaDist
 	AttributeKeyInflation               = types.AttributeKeyInflation
 	AttributeKeyStatus                  = types.AttributeKeyStatus
 	AttributeValueInactive              = types.AttributeValueInactive
-	DefaultParamspace      = types.DefaultParamspace
-	EventTypeKavaDist      = types.EventTypeKavaDist
-	KavaDistMacc           = types.KavaDistMacc
 	ModuleName                          = types.ModuleName
-	QuerierRoute           = types.QuerierRoute
-	QueryGetBalance        = types.QueryGetBalance
-	QueryGetParams         = types.QueryGetParams
-	RouterKey              = types.RouterKey
 	StoreKey                            = types.StoreKey
+	RouterKey                           = types.RouterKey
+	QuerierRoute                        = types.QuerierRoute
+	DefaultParamspace                   = types.DefaultParamspace
+	KavaDistMacc                        = types.KavaDistMacc
+	ProposalTypeCommunityPoolMultiSpend = types.ProposalTypeCommunityPoolMultiSpend
+	QueryGetParams                      = types.QueryGetParams
+	QueryGetBalance                     = types.QueryGetBalance
 )
 
 var (
-	// function aliases
+	// functions aliases
-	NewKeeper           = keeper.NewKeeper
-	NewQuerier          = keeper.NewQuerier
-	DefaultGenesisState = types.DefaultGenesisState
-	DefaultParams       = types.DefaultParams
-	NewGenesisState     = types.NewGenesisState
-	NewParams           = types.NewParams
-	NewPeriod           = types.NewPeriod
-	ParamKeyTable       = types.ParamKeyTable
 	RegisterCodec                         = types.RegisterCodec
+	NewGenesisState                       = types.NewGenesisState
+	DefaultGenesisState                   = types.DefaultGenesisState
+	NewPeriod                             = types.NewPeriod
+	NewParams                             = types.NewParams
+	DefaultParams                         = types.DefaultParams
+	ParamKeyTable                         = types.ParamKeyTable
+	NewCommunityPoolMultiSpendProposal    = types.NewCommunityPoolMultiSpendProposal
+	NewKeeper                             = keeper.NewKeeper
+	HandleCommunityPoolMultiSpendProposal = keeper.HandleCommunityPoolMultiSpendProposal
+	NewQuerier                            = keeper.NewQuerier
 
 	// variable aliases
+	ModuleCdc                 = types.ModuleCdc
+	ErrInvalidProposalAmount  = types.ErrInvalidProposalAmount
+	ErrEmptyProposalRecipient = types.ErrEmptyProposalRecipient
 	CurrentDistPeriodKey      = types.CurrentDistPeriodKey
+	PreviousBlockTimeKey      = types.PreviousBlockTimeKey
+	KeyActive                 = types.KeyActive
+	KeyPeriods                = types.KeyPeriods
 	DefaultActive             = types.DefaultActive
 	DefaultPeriods            = types.DefaultPeriods
 	DefaultPreviousBlockTime  = types.DefaultPreviousBlockTime
 	GovDenom                  = types.GovDenom
-	KeyActive                = types.KeyActive
+	ProposalHandler           = client.ProposalHandler
-	KeyPeriods               = types.KeyPeriods
-	ModuleCdc                = types.ModuleCdc
-	PreviousBlockTimeKey     = types.PreviousBlockTimeKey
 )
 
 type (
-	Keeper       = keeper.Keeper
 	GenesisState                    = types.GenesisState
 	Params                          = types.Params
 	Period                          = types.Period
 	Periods                         = types.Periods
-	SupplyKeeper = types.SupplyKeeper
+	CommunityPoolMultiSpendProposal = types.CommunityPoolMultiSpendProposal
+	MultiSpendRecipient             = types.MultiSpendRecipient
+	MultiSpendRecipients            = types.MultiSpendRecipients
+	Keeper                          = keeper.Keeper
 )

x/kavadist/client/cli/tx.go

@@ -0,0 +1,93 @@
+package cli
+
+import (
+	"bufio"
+	"fmt"
+	"strings"
+
+	"github.com/spf13/cobra"
+
+	"github.com/cosmos/cosmos-sdk/client/context"
+	"github.com/cosmos/cosmos-sdk/codec"
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/version"
+	"github.com/cosmos/cosmos-sdk/x/auth"
+	"github.com/cosmos/cosmos-sdk/x/auth/client/utils"
+	"github.com/cosmos/cosmos-sdk/x/gov"
+
+	"github.com/kava-labs/kava/x/kavadist/types"
+)
+
+// GetCmdSubmitProposal implements the command to submit a community-pool multi-spend proposal
+func GetCmdSubmitProposal(cdc *codec.Codec) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "community-pool-multi-spend [proposal-file]",
+		Args:  cobra.ExactArgs(1),
+		Short: "Submit a community pool multi-spend proposal",
+		Long: strings.TrimSpace(
+			fmt.Sprintf(`Submit a community pool multi-spend proposal along with an initial deposit.
+The proposal details must be supplied via a JSON file.
+
+Example:
+$ %s tx gov submit-proposal community-pool-multi-spend <path/to/proposal.json> --from=<key_or_address>
+
+Where proposal.json contains:
+
+{
+  "title": "Community Pool Multi-Spend",
+  "description": "Pay many users some KAVA!",
+  "recipient_list": [
+		{
+			"address": "kava1mz2003lathm95n5vnlthmtfvrzrjkrr53j4464",
+			"amount": [
+				{
+					"denom": "ukava",
+					"amount": "1000000"
+				}
+			]
+		},
+		{
+			"address": "kava1zqezafa0luyetvtj8j67g336vaqtuudnsjq7vm",
+			"amount": [
+				{
+					"denom": "ukava",
+					"amount": "1000000"
+				}
+			]
+		}
+	],
+	"deposit": [
+		{
+			"denom": "ukava",
+			"amount": "1000000000"
+		}
+	]
+}
+`,
+				version.ClientName,
+			),
+		),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			inBuf := bufio.NewReader(cmd.InOrStdin())
+			txBldr := auth.NewTxBuilderFromCLI(inBuf).WithTxEncoder(utils.GetTxEncoder(cdc))
+			cliCtx := context.NewCLIContextWithInput(inBuf).WithCodec(cdc)
+
+			proposal, err := ParseCommunityPoolMultiSpendProposalJSON(cdc, args[0])
+			if err != nil {
+				return err
+			}
+
+			from := cliCtx.GetFromAddress()
+			content := types.NewCommunityPoolMultiSpendProposal(proposal.Title, proposal.Description, proposal.RecipientList)
+
+			msg := gov.NewMsgSubmitProposal(content, proposal.Deposit, from)
+			if err := msg.ValidateBasic(); err != nil {
+				return err
+			}
+
+			return utils.GenerateOrBroadcastMsgs(cliCtx, txBldr, []sdk.Msg{msg})
+		},
+	}
+
+	return cmd
+}

x/kavadist/client/cli/utils.go

@@ -0,0 +1,36 @@
+package cli
+
+import (
+	"io/ioutil"
+
+	"github.com/cosmos/cosmos-sdk/codec"
+	sdk "github.com/cosmos/cosmos-sdk/types"
+
+	"github.com/kava-labs/kava/x/kavadist/types"
+)
+
+type (
+	// CommunityPoolMultiSpendProposalJSON defines a CommunityPoolMultiSpendProposal with a deposit
+	CommunityPoolMultiSpendProposalJSON struct {
+		Title         string                     `json:"title" yaml:"title"`
+		Description   string                     `json:"description" yaml:"description"`
+		RecipientList types.MultiSpendRecipients `json:"recipient_list" yaml:"recipient_list"`
+		Deposit       sdk.Coins                  `json:"deposit" yaml:"deposit"`
+	}
+)
+
+// ParseCommunityPoolMultiSpendProposalJSON reads and parses a CommunityPoolMultiSpendProposalJSON from a file.
+func ParseCommunityPoolMultiSpendProposalJSON(cdc *codec.Codec, proposalFile string) (CommunityPoolMultiSpendProposalJSON, error) {
+	proposal := CommunityPoolMultiSpendProposalJSON{}
+
+	contents, err := ioutil.ReadFile(proposalFile)
+	if err != nil {
+		return proposal, err
+	}
+
+	if err := cdc.UnmarshalJSON(contents, &proposal); err != nil {
+		return proposal, err
+	}
+
+	return proposal, nil
+}

x/kavadist/client/proposal_handler.go

@@ -0,0 +1,13 @@
+package client
+
+import (
+	govclient "github.com/cosmos/cosmos-sdk/x/gov/client"
+
+	"github.com/kava-labs/kava/x/kavadist/client/cli"
+	"github.com/kava-labs/kava/x/kavadist/client/rest"
+)
+
+// community-pool multi-spend proposal handler
+var (
+	ProposalHandler = govclient.NewProposalHandler(cli.GetCmdSubmitProposal, rest.ProposalRESTHandler)
+)

x/kavadist/client/rest/rest.go

@@ -1,12 +1,48 @@
 package rest
 
 import (
+	"net/http"
+
 	"github.com/gorilla/mux"
 
 	"github.com/cosmos/cosmos-sdk/client/context"
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/types/rest"
+	"github.com/cosmos/cosmos-sdk/x/auth/client/utils"
+	"github.com/cosmos/cosmos-sdk/x/gov"
+	govrest "github.com/cosmos/cosmos-sdk/x/gov/client/rest"
+
+	"github.com/kava-labs/kava/x/kavadist/types"
 )
 
 // RegisterRoutes registers kavadist-related REST handlers to a router
 func RegisterRoutes(cliCtx context.CLIContext, r *mux.Router) {
 	registerQueryRoutes(cliCtx, r)
 }
+
+// ProposalRESTHandler returns a ProposalRESTHandler that exposes the community pool multi-spend REST handler with a given sub-route.
+func ProposalRESTHandler(cliCtx context.CLIContext) govrest.ProposalRESTHandler {
+	return govrest.ProposalRESTHandler{
+		SubRoute: types.ProposalTypeCommunityPoolMultiSpend,
+		Handler:  postProposalHandlerFn(cliCtx),
+	}
+}
+func postProposalHandlerFn(cliCtx context.CLIContext) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		var req CommunityPoolMultiSpendProposalReq
+		if !rest.ReadRESTReq(w, r, cliCtx.Codec, &req) {
+			return
+		}
+		req.BaseReq = req.BaseReq.Sanitize()
+		if !req.BaseReq.ValidateBasic(w) {
+			return
+		}
+		content := types.NewCommunityPoolMultiSpendProposal(req.Title, req.Description, req.RecipientList)
+		msg := gov.NewMsgSubmitProposal(content, req.Deposit, req.Proposer)
+		if err := msg.ValidateBasic(); err != nil {
+			rest.WriteErrorResponse(w, http.StatusBadRequest, err.Error())
+			return
+		}
+		utils.WriteGenerateStdTxResponse(w, cliCtx, req.BaseReq, []sdk.Msg{msg})
+	}
+}

x/kavadist/client/rest/utils.go

@@ -0,0 +1,21 @@
+package rest
+
+import (
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/types/rest"
+
+	"github.com/kava-labs/kava/x/kavadist/types"
+)
+
+type (
+	// CommunityPoolMultiSpendProposalReq defines a community pool multi-spend proposal request body.
+	CommunityPoolMultiSpendProposalReq struct {
+		BaseReq rest.BaseReq `json:"base_req" yaml:"base_req"`
+
+		Title         string                     `json:"title" yaml:"title"`
+		Description   string                     `json:"description" yaml:"description"`
+		RecipientList types.MultiSpendRecipients `json:"recipient_list" yaml:"recipient_list"`
+		Deposit       sdk.Coins                  `json:"deposit" yaml:"deposit"`
+		Proposer      sdk.AccAddress             `json:"proposer" yaml:"proposer"`
+	}
+)

x/kavadist/handler.go

@@ -3,6 +3,9 @@ package kavadist
 import (
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
+	govtypes "github.com/cosmos/cosmos-sdk/x/gov/types"
+	"github.com/kava-labs/kava/x/kavadist/keeper"
+	"github.com/kava-labs/kava/x/kavadist/types"
 )
 
 // NewHandler creates an sdk.Handler for kavadist messages
@@ -15,3 +18,15 @@ func NewHandler(k Keeper) sdk.Handler {
 		}
 	}
 }
+
+func NewCommunityPoolMultiSpendProposalHandler(k Keeper) govtypes.Handler {
+	return func(ctx sdk.Context, content govtypes.Content) error {
+		switch c := content.(type) {
+		case types.CommunityPoolMultiSpendProposal:
+			return keeper.HandleCommunityPoolMultiSpendProposal(ctx, k, c)
+
+		default:
+			return sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "unrecognized kavadist proposal content type: %T", c)
+		}
+	}
+}

x/kavadist/keeper/keeper.go

@@ -17,10 +17,16 @@ type Keeper struct {
 	cdc           *codec.Codec
 	paramSubspace subspace.Subspace
 	supplyKeeper  types.SupplyKeeper
+	distKeeper    types.DistKeeper
+
+	blacklistedAddrs map[string]bool
 }
 
 // NewKeeper creates a new keeper
-func NewKeeper(cdc *codec.Codec, key sdk.StoreKey, paramstore subspace.Subspace, sk types.SupplyKeeper) Keeper {
+func NewKeeper(
+	cdc *codec.Codec, key sdk.StoreKey, paramstore subspace.Subspace, sk types.SupplyKeeper,
+	dk types.DistKeeper, blacklistedAddrs map[string]bool,
+) Keeper {
 	if !paramstore.HasKeyTable() {
 		paramstore = paramstore.WithKeyTable(types.ParamKeyTable())
 	}
@@ -30,6 +36,8 @@ func NewKeeper(cdc *codec.Codec, key sdk.StoreKey, paramstore subspace.Subspace,
 		cdc:              cdc,
 		paramSubspace:    paramstore,
 		supplyKeeper:     sk,
+		distKeeper:       dk,
+		blacklistedAddrs: blacklistedAddrs,
 	}
 }
 

x/kavadist/keeper/proposal_handler.go

@@ -0,0 +1,23 @@
+package keeper
+
+import (
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
+
+	"github.com/kava-labs/kava/x/kavadist/types"
+)
+
+// HandleCommunityPoolMultiSpendProposal is a handler for executing a passed community multi-spend proposal
+func HandleCommunityPoolMultiSpendProposal(ctx sdk.Context, k Keeper, p types.CommunityPoolMultiSpendProposal) error {
+	for _, receiverInfo := range p.RecipientList {
+		if k.blacklistedAddrs[receiverInfo.Address.String()] {
+			return sdkerrors.Wrapf(sdkerrors.ErrUnauthorized, "%s is blacklisted from receiving external funds", receiverInfo.Address)
+		}
+		err := k.distKeeper.DistributeFromFeePool(ctx, receiverInfo.Amount, receiverInfo.Address)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}

x/kavadist/types/codec.go

@@ -14,4 +14,5 @@ func init() {
 
 // RegisterCodec registers the necessary types for cdp module
 func RegisterCodec(cdc *codec.Codec) {
+	cdc.RegisterConcrete(CommunityPoolMultiSpendProposal{}, "kava/CommunityPoolMultiSpendProposal", nil)
 }

x/kavadist/types/errors.go

@@ -0,0 +1,11 @@
+package types
+
+import (
+	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
+)
+
+// x/kavadist errors
+var (
+	ErrInvalidProposalAmount  = sdkerrors.Register(ModuleName, 2, "invalid community pool multi-spend proposal amount")
+	ErrEmptyProposalRecipient = sdkerrors.Register(ModuleName, 3, "invalid community pool multi-spend proposal recipient")
+)

x/kavadist/types/expected_keepers.go

@@ -13,3 +13,8 @@ type SupplyKeeper interface {
 	SendCoinsFromModuleToModule(ctx sdk.Context, senderModule, recipientModule string, amt sdk.Coins) error
 	MintCoins(ctx sdk.Context, name string, amt sdk.Coins) error
 }
+
+// DistKeeper defines the expected distribution keeper interface
+type DistKeeper interface {
+	DistributeFromFeePool(ctx sdk.Context, amount sdk.Coins, receiveAddr sdk.AccAddress) error
+}

x/kavadist/types/proposal.go

@@ -0,0 +1,120 @@
+package types
+
+import (
+	"fmt"
+	"strings"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	govtypes "github.com/cosmos/cosmos-sdk/x/gov/types"
+)
+
+const (
+	// ProposalTypeCommunityPoolMultiSpend defines the type for a CommunityPoolMultiSpendProposal
+	ProposalTypeCommunityPoolMultiSpend = "CommunityPoolMultiSpend"
+)
+
+// Assert CommunityPoolMultiSpendProposal implements govtypes.Content at compile-time
+var _ govtypes.Content = CommunityPoolMultiSpendProposal{}
+
+func init() {
+	govtypes.RegisterProposalType(ProposalTypeCommunityPoolMultiSpend)
+	govtypes.RegisterProposalTypeCodec(CommunityPoolMultiSpendProposal{}, "kava/CommunityPoolMultiSpendProposal")
+}
+
+// CommunityPoolMultiSpendProposal spends from the community pool by sending to one or more addresses
+type CommunityPoolMultiSpendProposal struct {
+	Title         string               `json:"title" yaml:"title"`
+	Description   string               `json:"description" yaml:"description"`
+	RecipientList MultiSpendRecipients `json:"recipient_list" yaml:"recipient_list"`
+}
+
+// NewCommunityPoolMultiSpendProposal creates a new community pool multi-spend proposal.
+func NewCommunityPoolMultiSpendProposal(title, description string, recipientList MultiSpendRecipients) CommunityPoolMultiSpendProposal {
+	return CommunityPoolMultiSpendProposal{
+		Title:         title,
+		Description:   description,
+		RecipientList: recipientList}
+}
+
+// GetTitle returns the title of a community pool multi-spend proposal.
+func (csp CommunityPoolMultiSpendProposal) GetTitle() string { return csp.Title }
+
+// GetDescription returns the description of a community pool multi-spend proposal.
+func (csp CommunityPoolMultiSpendProposal) GetDescription() string { return csp.Description }
+
+// GetDescription returns the routing key of a community pool multi-spend proposal.
+func (csp CommunityPoolMultiSpendProposal) ProposalRoute() string { return RouterKey }
+
+// ProposalType returns the type of a community pool multi-spend proposal.
+func (csp CommunityPoolMultiSpendProposal) ProposalType() string {
+	return ProposalTypeCommunityPoolMultiSpend
+}
+
+// ValidateBasic stateless validation of a community pool multi-spend proposal.
+func (csp CommunityPoolMultiSpendProposal) ValidateBasic() error {
+	err := govtypes.ValidateAbstract(csp)
+	if err != nil {
+		return err
+	}
+	if err := csp.RecipientList.Validate(); err != nil {
+		return err
+	}
+	return nil
+}
+
+// String implements fmt.Stringer
+func (csp CommunityPoolMultiSpendProposal) String() string {
+	var b strings.Builder
+	b.WriteString(fmt.Sprintf(`Community Pool Multi Spend Proposal:
+  Title:       %s
+  Description: %s
+  Recipient List:   %s
+`, csp.Title, csp.Description, csp.RecipientList))
+	return b.String()
+}
+
+// MultiSpendRecipient defines a recipient and the amount of coins they are receiving
+type MultiSpendRecipient struct {
+	Address sdk.AccAddress `json:"address" yaml:"address"`
+	Amount  sdk.Coins      `json:"amount" yaml:"amount"`
+}
+
+// Validate stateless validation of MultiSpendRecipient
+func (msr MultiSpendRecipient) Validate() error {
+	if !msr.Amount.IsValid() {
+		return ErrInvalidProposalAmount
+	}
+	if msr.Address.Empty() {
+		return ErrEmptyProposalRecipient
+	}
+	return nil
+}
+
+// String implements fmt.Stringer
+func (msr MultiSpendRecipient) String() string {
+	return fmt.Sprintf(`Receiver: %s
+	Amount: %s
+	`, msr.Address, msr.Amount)
+}
+
+// MultiSpendRecipients slice of MultiSpendRecipient
+type MultiSpendRecipients []MultiSpendRecipient
+
+// Validate stateless validation of MultiSpendRecipients
+func (msrs MultiSpendRecipients) Validate() error {
+	for _, msr := range msrs {
+		if err := msr.Validate(); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// String implements fmt.Stringer
+func (msrs MultiSpendRecipients) String() string {
+	out := ""
+	for _, msr := range msrs {
+		out += msr.String()
+	}
+	return out
+}