code: protected void prepareDirectories() throws ManagedProcessException {
          baseDir = Util.getDirectory(configuration.getBaseDir());
          libDir = Util.getDirectory(configuration.getLibDir());
          try {
              String dataDirPath = configuration.getDataDir();
              if (Util.isTemporaryDirectory(dataDirPath)) {
                  FileUtils.deleteDirectory(new File(dataDirPath));
              }
              dataDir = Util.getDirectory(dataDirPath);
          } catch (Exception e) {
              throw new ManagedProcessException("An error occurred while preparing the data directory", e);
          }
      }
docs: If the data directory specified in the configuration is a temporary directory, this deletes
  any previous version. It also makes sure that the directory exists.
  
  @throws ManagedProcessException if something fatal went wrong