@Override
public void setUp() throws Exception{
Logger logger = Logger.getLogger(ColumnPruneVisitor.class);
logger.removeAllAppenders();
logger.setLevel(Level.INFO);
SimpleLayout layout = new SimpleLayout();
logFile = File.createTempFile("log", "");
FileAppender appender = new FileAppender(layout, logFile.toString(), false, false, 0);
logger.addAppender(appender);
Logger pigStorageWithTraceLogger = Logger.getLogger(PigStorageWithTrace.class);