   $('.show-childrens').click ->
     parent_id = $(this).parents('.panel-container').attr('id')
     parent_content = $(this).parent().next('.panel_contents')
-
     # NOTE: do not use .toggleClass here
     if parent_content.is(':hidden')
       parent_content.show()

    content = $(this).parent().next('.panel_contents')
    if content.is(':hidden')
      content.show('fast')
    else
      content.hide('fast')


  $('.panel-header').on 'click', ->
    clearAllColors()
    $(this).addClass('selectable')
    # add color to all node's panel headers
    parent_id = $(this).parents('.panel-container').attr('id')
    $('.panel-header').each ->
