needKeepAlive() {
    // TODO: check version also (geth version < 1.8.15)
    if (this.isDev) {
      // Trigger regular txs due to a bug in geth (< 1.8.15) and stuck transactions in --dev mode.
      return true;
    }
    return false;
  }
Check if the client needs some sort of 'keep alive' transactions to avoid freezing by inactivity
@returns {boolean} if keep alive is needed