How to use the bsv.MerkleBlock function in bsv

if (gene.chain) {
      this.chain = gene.chain;
      this.chainPath = (this.chain.path ? this.chain.path : process.cwd() + "/chain");
      if (!fs.existsSync(this.chainPath)) fs.mkdirSync(this.chainPath, { recursive: true })
    }

    // RPC
    const rpcconfig = Object.assign({
      protocol: "http",
      host: "127.0.0.1",
      port: "8332",
    }, (gene && gene.rpc ? gene.rpc : {}))
    this.rpc = new RpcClient(rpcconfig)

    // PEER
    let m = new Messages({ Block: bsv.Block, BlockHeader: bsv.BlockHeader, Transaction: bsv.Transaction, MerkleBlock: bsv.MerkleBlock, network: bsv.Networks.defaultNetwork })
    let g = Object.assign({ host: "127.0.0.1", messages: m }, (gene && gene.peer ? gene.peer : {}))
    this.peer = new Peer(g)
    this.peer.on("disconnect", function() { console.log("disconnected") })
    this.peer.on("error", function(e) { console.log("Err", e) })
    this.peer.on("notfound", function(e) { console.log("notfound", e) })
    this.peer.on("reject", function(e) { console.log("reject", e) })
    this.peer.on('block', async (e) => {
      let header = e.block.header.toObject()
      if (this.onblock) {
        if (this.request.type.includes('block')) {
          let index = this.request.type.indexOf("block");
          if (index > -1) this.request.type.splice(index, 1)
          header.height = this.current_block.height
        } else if (this.request.type.includes('onblock')) {
          header.height = await this.height(header.hash)
        }

const log = require("debug")("hummingbird");

const { Peer, Messages } = require("bsv-p2p");
import bsv from "bsv"
import RPCClient from "bitcoind-rpc"
import txo from "txo"
import Queue from "promise-queue"

import * as tape from "./tape"
import { sleep } from "./helpers"


const messages = new Messages({ Block: bsv.Block, BlockHeader: bsv.BlockHeader, Transaction: bsv.Transaction, MerkleBlock: bsv.MerkleBlock });

const STATE = {
    DISCONNECTED: "DISCONNECTED",
    CONNECTING: "CONNECTING",
    CRAWLING: "CRAWLING",
    LISTENING: "LISTENING",
};

const MODE = {
    BOTH: "BOTH",
    MEMPOOL: "MEMPOOL",
    BLOCK: "BLOCK",
};

export default class Hummingbird {