@VisibleForTesting
  void checkRemoteFoldernameField( String remoteFoldernameFieldName, SFTPPutData data ) throws KettleStepException {
    // Remote folder fieldname
    remoteFoldernameFieldName = environmentSubstitute( remoteFoldernameFieldName );
    if ( Utils.isEmpty( remoteFoldernameFieldName ) ) {
      // remote folder field is missing
      throw new KettleStepException( BaseMessages.getString( PKG, "SFTPPut.Error.RemoteFolderNameFieldMissing" ) );
    }

    data.indexOfRemoteDirectory = getInputRowMeta().indexOfValue( remoteFoldernameFieldName );
    if ( data.indexOfRemoteDirectory == -1 ) {
      // remote foldername field is missing
      throw new KettleStepException( BaseMessages.getString(
        PKG, "SFTPPut.Error.CanNotFindField", remoteFoldernameFieldName ) );
    }
  }
@Test( expected = KettleStepException.class )
  public void checkRemoteFoldernameField_NameIsBlank() throws Exception {
    SFTPPutData data = new SFTPPutData();
    step.checkRemoteFoldernameField( "", data );
  }