### Question:
CronUtils { public static String getMonthlyCronExpression( int minutes, int hours, int dayOfMonth ) { return getCronExpression( "0", String.valueOf( minutes ), String.valueOf( hours ), String.valueOf( dayOfMonth ), "*/1", null ); }  static String getDailyCronExpression( int minutes, int hours ); static String getWeeklyCronExpression( int minutes, int hours, int dayOfWeek ); static String getMonthlyCronExpression( int minutes, int hours, int dayOfMonth ); static String getCronExpression( String seconds, String minutes, String hours, String days, String months,
        String weekday );  }### Answer:
@Test public void getMonthlyCronExpression() { assertEquals( "0 0 0 15 */1 *", CronUtils.getMonthlyCronExpression( 0, 0, 15 ) ); }