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

connect () {
    // signal through all available signaling connections
    announceSignalingInfo(this)
    const roomName = this.name
    bc.subscribe(roomName, this._bcSubscriber)
    this.bcconnected = true
    // broadcast peerId via broadcastchannel
    broadcastBcPeerId(this)
    // write sync step 1
    const encoderSync = encoding.createEncoder()
    encoding.writeVarUint(encoderSync, messageSync)
    syncProtocol.writeSyncStep1(encoderSync, this.doc)
    broadcastBcMessage(this, encoding.toUint8Array(encoderSync))
    // broadcast local state
    const encoderState = encoding.createEncoder()
    encoding.writeVarUint(encoderState, messageSync)
    syncProtocol.writeSyncStep2(encoderState, this.doc)
    broadcastBcMessage(this, encoding.toUint8Array(encoderState))
    // write queryAwareness
    const encoderAwarenessQuery = encoding.createEncoder()
    encoding.writeVarUint(encoderAwarenessQuery, messageQueryAwareness)
    broadcastBcMessage(this, encoding.toUint8Array(encoderAwarenessQuery))
    // broadcast local awareness state
    const encoderAwarenessState = encoding.createEncoder()
    encoding.writeVarUint(encoderAwarenessState, messageAwareness)
    encoding.writeVarUint8Array(encoderAwarenessState, awarenessProtocol.encodeAwarenessUpdate(this.awareness, [this.doc.clientID]))
    broadcastBcMessage(this, encoding.toUint8Array(encoderAwarenessState))

connect () {
    // signal through all available signaling connections
    announceSignalingInfo(this)
    const roomName = this.name
    bc.subscribe(roomName, this._bcSubscriber)
    this.bcconnected = true
    // broadcast peerId via broadcastchannel
    broadcastBcPeerId(this)
    // write sync step 1
    const encoderSync = encoding.createEncoder()
    encoding.writeVarUint(encoderSync, messageSync)
    syncProtocol.writeSyncStep1(encoderSync, this.doc)
    broadcastBcMessage(this, encoding.toUint8Array(encoderSync))
    // broadcast local state
    const encoderState = encoding.createEncoder()
    encoding.writeVarUint(encoderState, messageSync)
    syncProtocol.writeSyncStep2(encoderState, this.doc)
    broadcastBcMessage(this, encoding.toUint8Array(encoderState))
    // write queryAwareness
    const encoderAwarenessQuery = encoding.createEncoder()
    encoding.writeVarUint(encoderAwarenessQuery, messageQueryAwareness)
    broadcastBcMessage(this, encoding.toUint8Array(encoderAwarenessQuery))
    // broadcast local awareness state
    const encoderAwarenessState = encoding.createEncoder()
    encoding.writeVarUint(encoderAwarenessState, messageAwareness)
    encoding.writeVarUint8Array(encoderAwarenessState, awarenessProtocol.encodeAwarenessUpdate(this.awareness, [this.doc.clientID]))
    broadcastBcMessage(this, encoding.toUint8Array(encoderAwarenessState))
  }
  disconnect () {

export const writeID = (encoder, id) => {
  encoding.writeVarUint(encoder, id.client)
  encoding.writeVarUint(encoder, id.clock)
}

_toBinary (encoder) {
    encoding.writeUint8(encoder, getStructReference(this.constructor))
    this._targetID.encode(encoder)
    encoding.writeVarUint(encoder, this._length)
  }

_write (encoder) {
    encoding.writeVarUint(encoder, YTextRefID)
  }
}

export const writeDeleteSet = (encoder, ds) => {
  encoding.writeVarUint(encoder, ds.clients.size)
  ds.clients.forEach((dsitems, client) => {
    encoding.writeVarUint(encoder, client)
    const len = dsitems.length
    encoding.writeVarUint(encoder, len)
    for (let i = 0; i < len; i++) {
      const item = dsitems[i]
      encoding.writeVarUint(encoder, item.clock)
      encoding.writeVarUint(encoder, item.len)
    }
  })
}

_write (encoder) {
    encoding.writeVarUint(encoder, YMapRefID)
  }
}

_write (encoder) {
    super._write(encoder)
    encoding.writeVarUint(encoder, YXmlHookRefID)
    encoding.writeVarString(encoder, this.hookName)
  }
}

ds.clients.forEach((dsitems, client) => {
    encoding.writeVarUint(encoder, client)
    const len = dsitems.length
    encoding.writeVarUint(encoder, len)
    for (let i = 0; i < len; i++) {
      const item = dsitems[i]
      encoding.writeVarUint(encoder, item.clock)
      encoding.writeVarUint(encoder, item.len)
    }
  })
}