How to use the lib0/encoding.js.toBuffer function in lib0

if (conns.length > 0) {
      const receiver = random.oneOf(prng, conns)
      const [sender, messages] = random.oneOf(prng, Array.from(receiver.receiving))
      const m = messages.shift()
      if (messages.length === 0) {
        receiver.receiving.delete(sender)
      }
      const encoder = encoding.createEncoder()
      receiver.mMux(() => {
        // console.log('receive (' + sender.userID + '->' + receiver.userID + '):\n', syncProtocol.stringifySyncMessage(decoding.createDecoder(m), receiver))
        // do not publish data created when this function is executed (could be ss2 or update message)
        syncProtocol.readSyncMessage(decoding.createDecoder(m), encoder, receiver)
      })
      if (encoding.length(encoder) > 0) {
        // send reply message
        sender._receive(encoding.toBuffer(encoder), receiver)
      }
      return true
    }
    return false
  }
  /**

this.tc.onlineConns.forEach(remoteYInstance => {
        if (remoteYInstance !== this) {
          // remote instance sends instance to this instance
          const encoder = encoding.createEncoder()
          syncProtocol.writeSyncStep1(encoder, remoteYInstance)
          this._receive(encoding.toBuffer(encoder), remoteYInstance)
        }
      })
    }

connect () {
    if (!this.tc.onlineConns.has(this)) {
      this.tc.onlineConns.add(this)
      const encoder = encoding.createEncoder()
      syncProtocol.writeSyncStep1(encoder, this)
      // publish SyncStep1
      broadcastMessage(this, encoding.toBuffer(encoder))
      this.tc.onlineConns.forEach(remoteYInstance => {
        if (remoteYInstance !== this) {
          // remote instance sends instance to this instance
          const encoder = encoding.createEncoder()
          syncProtocol.writeSyncStep1(encoder, remoteYInstance)
          this._receive(encoding.toBuffer(encoder), remoteYInstance)
        }
      })
    }
  }
  /**

y.mMux(() => {
    if (transaction.encodedStructsLen > 0) {
      const encoder = encoding.createEncoder()
      syncProtocol.writeUpdate(encoder, transaction.encodedStructsLen, transaction.encodedStructs)
      broadcastMessage(y, encoding.toBuffer(encoder))
    }
  })
}