anchor.diff:      // then remove
       var template = `<%= load_course_lesson_form_view(nil) %>`;
       function reorder(){
  -      course_lessons_sort.sortable();
  +      sortable(course_lessons_sort);
         updateNestedfields();
       };
       searchable_input(insertedItem.clone(),
  
positive.code:   </div>
    <div id='course_lessons' >
      <div class='links'>
        <%= link_to_add_association 'Add Lesson to Course', f, :course_lessons, :class => "btn btn-raised" %>
      </div>
      <h4>Lessons:</h4>
      <div class="lesson_fields sortable">
  
negative.code:     set_positions();
    };
  
    var course_lessons_sort = '#course_lessons .sortable';
    sortable(course_lessons_sort, {
      items: ".nested-fields",
      hoverClass: 'sortable-item-hover'
    })[0].addEventListener('sortupdate', function(e) {
        updateNestedfields();
    });
    set_positions();
  