code: func netName(chainParams *chaincfg.Params) string {
  	switch chainParams.Net {
  	case wire.TestNet3:
  		return "testnet"
  	default:
  		return chainParams.Name
  	}
  }
docs: // netName returns the name used when referring to a bitcoin network.  At the
  // time of writing, btcd currently places blocks for testnet version 3 in the
  // data and log directory "testnet", which does not match the Name field of the
  // chaincfg parameters.  This function can be used to override this directory name
  // as "testnet" when the passed active network matches wire.TestNet3.
  //
  // A proper upgrade to move the data and log directories for this network to
  // "testnet3" is planned for the future, at which point this function can be
  // removed and the network parameter's name used instead.