// test.parentNode === my_document
true
// test2.parentNode === my_document
true
// test3.parentNode === my_document
true

// test.previousSibling === null
true
// test.nextSibling === test2
true

// test2.previousSibling === test
true
// test2.nextSibling === test3
true

// test3.previousSibling === test2
true
// test3.nextSibling === null
true

// my_document.childNodes[0] === test
true
// my_document.childNodes[1] === test2
true
// my_document.childNodes[2] === test3
true

