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: multi_target_balancer_test.go
    path of file: ./repos/milvus/internal/querycoordv2/balance
    
    the code of the file until where you have to start completion: package balance

import (
	"math/rand"
	"testing"
	"time"

	"github.com/samber/lo"
	"github.com/stretchr/testify/suite"

	"github.com/milvus-io/milvus/internal/proto/datapb"
	"github.com/milvus-io/milvus/internal/querycoordv2/meta"
	"github.com/milvus-io/milvus/pkg/util/paramtable"
	"github.com/milvus-io/milvus/pkg/util/typeutil"
)

type MultiTargetBalancerTestSuite struct {
	suite.Suite
}

func (suite *MultiTargetBalancerTestSuite) SetupSuite() {
	paramtable.Init()
	rand.Seed(time.Now().UnixNano())
}

func (suite *MultiTargetBalancerTestSuite) TestRowCountCostModel() {
	cases := [][]struct {
		nodeID    int64
		segmentID int64
		rowCount  int64
	}{
		//
    
func (suite *MultiTargetBalancerTestSuite) TestRandomPlanGenerator() {
	cases := []struct {
		nodeSegments map[int64][]*meta.Segment
		expectCost   float64
	}{
		// case 1
		{
			map[int64][]*meta.Segment{
				1: {
					{SegmentInfo: &datapb.SegmentInfo{ID: 1, NumOfRows: 20}}, {SegmentInfo: &datapb.SegmentInfo{ID: 2, NumOfRows: 30}},
				},
				2: {
					{SegmentInfo: &datapb.SegmentInfo{ID: 3, NumOfRows: 20}},
					{SegmentInfo: &datapb.SegmentInfo{ID: 4, NumOfRows: 10}},
				},
			},
			0,
		},
	}

	for _, c := range cases {
		generator := newRandomPlanGenerator(100) // set a large enough random steps
		generator.setReplicaNodeSegments(c.nodeSegments)
		generator.setGlobalNodeSegments(c.nodeSegments)
		generator.generatePlans()
		suite.InDelta(c.expectCost, generator.currClusterCost, 0.001)
	}
}