code: protected boolean acceptFile(FileStatus fileStatus) {
  		final String name = fileStatus.getPath().getName();
  		return !name.startsWith("_") && !name.startsWith(".");
  	}
docs: A simple hook to filter files and directories from the input.
  The method may be overridden. Hadoop's FileInputFormat has a similar mechanism and applies the
  same filters by default.
  
  @param fileStatus
  @return true, if the given file or directory is accepted