code: protected File getDir(String pdbId, boolean obsolete) {
  
  		File dir = null;
  
  		if (obsolete) {
  			// obsolete is always split
  			String middle = pdbId.substring(1,3).toLowerCase();
  			dir = new File(obsoleteDirPath, middle);
  		} else {
  			String middle = pdbId.substring(1,3).toLowerCase();
  			dir = new File(splitDirPath, middle);
  		}
  
  
  		if (!dir.exists()) {
  			boolean success = dir.mkdirs();
  			if (!success) logger.error("Could not create mmCIF dir {}",dir.toString());
  		}
  
  		return dir;
  	}
docs: Gets the directory in which the file for a given MMCIF file would live,
  creating it if necessary.
  
  The obsolete parameter is necessary to avoid additional server queries.
  @param pdbId
  @param obsolete Whether the pdbId is obsolete or not
  @return File pointing to the directory,