You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: msg_server_test.go
    path of file: ./repos/cosmos-sdk/x/nft/keeper
    
    the code of the file until where you have to start completion: package keeper_test

import (
	"fmt"

	"cosmossdk.io/x/nft"
)

var (
	ExpClass = nft.Class{
		Id:          testClassID,
		Name:        testClassName,
		Symbol:      testClassSymbol,
		Description: testClassDescription,
		Uri:         testClassURI,
		UriHash:     testClassURIHash,
	}

	ExpNFT = nft.NFT{
		ClassId: testClassID,
		Id:      testID,
		Uri:     testURI,
	}
)

func (s *TestSuite) TestSend() {
	err := s.nftKeeper.SaveClass(s.ctx, ExpClass)
	s.Require().NoError(err)

	actual, has := s.nftKeeper.GetClass(s.ctx, testClassID)
	s.Require().True(has)
	s.Require().EqualValues(ExpClass, actual)

	err = s.nftKeeper.Mint(s.ctx, ExpNFT, s.addrs[0])
	s.Require().NoError(err)

	expGenesis := &nft.GenesisState{
		Classes: []*nft.Class{&ExpClass},
		Entries: []*nft.Entry{{
			Owner: s.encodedAddrs[0],
			Nfts:  []*nft.NFT{&ExpNFT},
		}},
	}
	genesis := s.nftKeeper.ExportGenesis(s.ctx)
	s.Require().Equal(expGenesis, genesis)

	testCases := []struct {
		name   string
		req    *nft.MsgSend
		expErr bool
		errMsg string
	}{
		{
			name: "empty nft id",
			req: &nft.MsgSend{
				ClassId:  testClassID,
				Id:       "",
				Sender:   s.encodedAddrs[0],
				Receiver: s.encodedAddrs[1],
			},
			expErr: true,
			errMsg: "empty nft id",
		},
		{
			name: "empty class id",
			req: &nft.MsgSend{
				ClassId:  "",
				Id:       testID,
				Sender:   s.encodedAddrs[0],
				Receiver: s.encodedAddrs[1],
			},
			expErr: true,
			errMsg: "empty class id",
		},
		{
			name: "invalid class id",
			req: &nft.MsgSend{
				ClassId:  "invalid ClassId",
				Id:       testID,
				Sender:   s.encodedAddrs[0],
				Receiver: s.encodedAddrs[1],
			},
			expErr: true,
			errMsg: "unauthorized",
		},
		{
			name: "invalid nft id",
			req: &nft.MsgSend{
				ClassId:  testClassID,
				Id:       "invalid Id",
				Sender:   s.encodedAddrs[0],
				Receiver: s.encodedAddrs[1],
			},
			expErr: true,
			errMsg: "unauthorized",
		},
		{
			name: "unauthorized sender",
			req: &nft.MsgSend{
				ClassId:  testClassID,
				Id:       testID,
				Sender:   s.encoded
    
func (s *TestSuite) TestSend() {
	err := s.nftKeeper.SaveClass(s.ctx, ExpClass)
	s.Require().NoError(err)

	actual, has := s.nftKeeper.GetClass(s.ctx, testClassID)
	s.Require().True(has)
	s.Require().EqualValues(ExpClass, actual)

	err = s.nftKeeper.Mint(s.ctx, ExpNFT, s.addrs[0])
	s.Require().NoError(err)

	expGenesis := &nft.GenesisState{
		Classes: []*nft.Class{&ExpClass},
		Entries: []*nft.Entry{{
			Owner: s.encodedAddrs[0],
			Nfts:  []*nft.NFT{&ExpNFT},
		}},
	}
	genesis := s.nftKeeper.ExportGenesis(s.ctx)
	s.Require().Equal(expGenesis, genesis)

	testCases := []struct {
		name   string
		req    *nft.MsgSend
		expErr bool
		errMsg string
	}{
		{
			name: "empty nft id",
			req: &nft.MsgSend{
				ClassId:  testClassID,
				Id:       "",
				Sender:   s.encodedAddrs[0],
				Receiver: s.encodedAddrs[1],
			},
			expErr: true,
			errMsg: "empty nft id",
		},
		{
			name: "empty class id",
			req: &nft.MsgSend{
				ClassId:  "",
				Id:       testID,
				Sender:   s.encodedAddrs[0],
				Receiver: s.encodedAddrs[1],
			},
			expErr: true,
			errMsg: "empty class id",
		},
		{
			name: "invalid class id",
			req: &nft.MsgSend{
				ClassId:  "invalid ClassId",
				Id:       testID,
				Sender:   s.encodedAddrs[0],
				Receiver: s.encodedAddrs[1],
			},
			expErr: true,
			errMsg: "unauthorized",
		},
		{
			name: "invalid nft id",
			req: &nft.MsgSend{
				ClassId:  testClassID,
				Id:       "invalid Id",
				Sender:   s.encodedAddrs[0],
				Receiver: s.encodedAddrs[1],
			},
			expErr: true,
			errMsg: "unauthorized",
		},
		{
			name: "unauthorized sender",
			req: &nft.MsgSend{
				ClassId:  testClassID,
				Id:       testID,
				Sender:   s.encodedAddrs[1],
				Receiver: s.encodedAddrs[2],
			},
			expErr: true,
			errMsg: fmt.Sprintf("%s is not the owner of nft %s", s.encodedAddrs[1], testID),
		},
		{
			name: "valid transaction",
			req: &nft.MsgSend{
				ClassId:  testClassID,
				Id:       testID,
				Sender:   s.encodedAddrs[0],
				Receiver: s.encodedAddrs[1],
			},
			expErr: false,
			errMsg: "",
		},
	}

	for _, tc := range testCases {
		s.Run(tc.name, func() {
			_, err := s.nftKeeper.Send(s.ctx, tc.req)
			if tc.expErr {
				s.Require().Error(err)
				s.Require().Contains(err.Error(), tc.errMsg)
			} else {
				s.Require().NoError(err)
			}
		})
	}
}