How jQuery END works

jquery_end_example.js

$('#lists')
  .find(' > li') // FILTER1 #lists > li
  .filter('li:last') // FILTER1_1 #lists > li:last
  .addClass('coloring2')
  .end() // go back to previous filter: FILTER1 #lists > li
  .find('ul') // FILTER1_2: find ul inside #lists > li
  .filter('> li') // FILTER1_2_1: ul > li inside #lists > li
  .addClass('coloring')
  .end() // go back one filter FILTER1_2
  .end() // go back one filter FILTER1
  .end() // go back one filter NO FILTER
  .find('li') // FILTER2 #lists > li
  .appendTo('body');
//===================