code: package org.rug.args;
  
  import com.beust.jcommander.IStringConverter;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.io.File;
  
  public class OutputDirManager implements IStringConverter<File> {
  
      private final static Logger logger = LoggerFactory.getLogger(OutputDirManager.class);
  
      @Override
      public File convert(String s) {
          File f = new File(s);
          if (!f.exists()) {
              if(!f.mkdirs()) {
                  logger.error("Unable to create outputDir directory: {}", s);
                  throw new IllegalArgumentException();
              }
          }
          return f;
      }
  }
  