How to use the ipns.getLocalKey function in ipns

entryData = await ipns.create(privKey, value, seqNumber, validity)
    } catch (err) {
      const errMsg = `ipns record for ${value} could not be created`

      log.error(err)
      throw errcode(new Error(errMsg), 'ERR_CREATING_IPNS_RECORD')
    }

    // TODO IMPROVEMENT - set ttl (still experimental feature for go)

    try {
      // Marshal record
      const data = ipns.marshal(entryData)

      // Store the new record
      await this._datastore.put(ipns.getLocalKey(peerId.id), data)

      log(`ipns record for ${value} was stored in the datastore`)

      return entryData
    } catch (err) {
      const errMsg = `ipns record for ${value} could not be stored in the datastore`
      log.error(errMsg)

      throw errcode(new Error(errMsg), 'ERR_STORING_IN_DATASTORE')
    }
  }
}

async _getPublished (peerId, options) {
    if (!(PeerId.isPeerId(peerId))) {
      const errMsg = 'peerId received is not valid'

      log.error(errMsg)

      throw errcode(new Error(errMsg), 'ERR_INVALID_PEER_ID')
    }

    options = options || {}
    const checkRouting = options.checkRouting !== false

    try {
      const dsVal = await this._datastore.get(ipns.getLocalKey(peerId.id))

      // unmarshal data
      return this._unmarshalData(dsVal)
    } catch (err) {
      if (err.code !== ERR_NOT_FOUND) {
        const errMsg = `unexpected error getting the ipns record ${peerId.id} from datastore`
        log.error(errMsg)

        throw errcode(new Error(errMsg), 'ERR_UNEXPECTED_DATASTORE_RESPONSE')
      }

      if (!checkRouting) {
        throw errcode(err)
      }

      // Try to get from routing

async _getPreviousValue (peerId) {
    if (!(PeerId.isPeerId(peerId))) {
      throw errcode(new Error('invalid peer ID'), 'ERR_INVALID_PEER_ID')
    }

    try {
      const dsVal = await this._datastore.get(ipns.getLocalKey(peerId.id))

      if (!Buffer.isBuffer(dsVal)) {
        throw errcode(new Error("found ipns record that we couldn't process"), 'ERR_INVALID_IPNS_RECORD')
      }

      // unmarshal data
      try {
        const record = ipns.unmarshal(dsVal)

        return record.value
      } catch (err) {
        log.error(err)
        throw errcode(new Error('found ipns record that we couldn\'t convert to a value'), 'ERR_INVALID_IPNS_RECORD')
      }
    } catch (err) {
      // error handling