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: environ_vpc_test.go
    path of file: ./repos/juju/provider/ec2
    
    the code of the file until where you have to start completion: // Copyright 2016 Canonical Ltd.
// Licensed under the AGPLv3, see LICENCE file for details.

package ec2

import (
	sdkcontext "context"
	"fmt"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/ec2"
	"github.com/aws/aws-sdk-go-v2/service/ec2/types"
	"github.com/aws/smithy-go"
	"github.com/juju/errors"
	"github.com/juju/testing"
	jc "github.com/juju/testing/checkers"
	gc "gopkg.in/check.v1"

	corenetwork "github.com/juju/juju/core/network"
	"github.com/juju/juju/environs/context"
	envtesting "github.com/juju/juju/environs/testing"
	"github.com/juju/juju/provider/common"
)

type vpcSuite struct {
	testing.IsolationSuite

	stubAPI *stu
    
func makeEC2RouteTable(tableID string, isMain bool, associatedSubnetIDs []string, routes []types.Route) types.RouteTable {
	table := types.RouteTable{
		RouteTableId: aws.String(tableID),
		VpcId:        aws.String(anyVPCID),
		Routes:       routes,
	}

	if isMain {
		table.Associations = []types.RouteTableAssociation{{
			RouteTableAssociationId: aws.String("rtbassoc-main"),
			RouteTableId:            aws.String(tableID),
			Main:                    aws.Bool(true),
		}}
	} else {
		table.Associations = make([]types.RouteTableAssociation, len(associatedSubnetIDs))
		for i := range associatedSubnetIDs {
			table.Associations[i] = types.RouteTableAssociation{
				RouteTableAssociationId: aws.String(fmt.Sprintf("rtbassoc-%d", i)),
				RouteTableId:            aws.String(tableID),
				SubnetId:                aws.String(associatedSubnetIDs[i]),
			}
		}
	}
	return table
}