protected void sendVisitsQueryByLessonSelect(GroupLesson lesson) {
   for (GroupLesson gLesson : jC.getLessons(selectedGroup, selectedSemester)) {
     if (gLesson.equals(lesson)) {
       selectedLesson = gLesson;
       break;
     }
   }
   jC.sendGroupVisitsQuery(selectedLesson);
 }
 protected void restoreLessonStudents() {
   if (jC.getVisits() != null) lessonsSelector.setLessonTitle(selectedLesson);
   if (!selectedGroup.isEmpty() && selectedLesson != null) {
     lessonsSelector.restoreState(jC.getLessons(selectedGroup, selectedSemester));
     studentList.restoreState(jC.getStudents(selectedGroup));
   } else {
     groupSelectorSeparateLine.setVisibility(View.INVISIBLE);
   }
 }