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: params_mainnet.go
    path of file: ./repos/lotus/build
    
    the code of the file until where you have to start completion: //go:build !debug && !2k && !testground && !calibnet && !butterflynet && !interopnet
// +build !debug,!2k,!testground,!calibnet,!butterflynet,!interopnet

package build

import (
	"math"
	"os"
	"strconv"

	"github.com/filecoin-project/go-address"
	"github.com/filecoin-project/go-state-types/abi"
	actorstypes "github.com/filecoin-project/go-state-types/actors"
	"github.com/filecoin-project/go-state-types/network"
	builtin2 "github.com/filecoin-project/specs-actors/v2/actors/builtin"
)

var DrandSchedule = map[abi.ChainEpoch]DrandEnum{
	0:                  DrandIncentinet,
	UpgradeSmokeHeight: DrandMainnet,
}

var NetworkBundle = "mainnet"

// NOTE: DO NOT change this unless you REALLY know what you're doing. This is consensus c
    
func init() {
	if os.Getenv("LOTUS_USE_TEST_ADDRESSES") != "1" {
		SetAddressNetwork(address.Mainnet)
	}

	if os.Getenv("LOTUS_DISABLE_WATERMELON") == "1" {
		UpgradeWatermelonHeight = math.MaxInt64
	}

	// NOTE: DO NOT change this unless you REALLY know what you're doing. This is not consensus critical, however,
	//set this value too high may impacts your block submission; set this value too low may cause you miss
	//parent tipsets for blocking forming and mining.
	if len(os.Getenv("PROPAGATION_DELAY_SECS")) != 0 {
		pds, err := strconv.ParseUint(os.Getenv("PROPAGATION_DELAY_SECS"), 10, 64)
		if err != nil {
			log.Warnw("Error setting PROPAGATION_DELAY_SECS, %v, proceed with default value %s", err,
				PropagationDelaySecs)
		} else {
			PropagationDelaySecs = pds
			log.Warnw(" !!WARNING!! propagation delay is set to be %s second, "+
				"this value impacts your message republish interval and block forming - monitor with caution!!", PropagationDelaySecs)
		}
	}

	Devnet = false

	BuildType = BuildMainnet
}