code: public static File [] listFiles(File file) {
  		if (file==null){
  			return EMPTY_FILE_LIST;
  		} 
  		
  		File ret[]=file.listFiles(FILE_FILTER);
  		
  		if (ret==null){
  			return EMPTY_FILE_LIST;
  		} else {
  			return ret;
  		}		
  	}
docs: Returns the child files if any, otherwise return new File[0]
  @param file
  @return