Finds all descendant elements of this document fragment that match the specified group of selectors.
selectors should be a string using CSS selector syntax.
var items = document.querySelectorAll('.itemClassName');
For details about CSS selector syntax, see the CSS selector specification.
Source
ElementList<Element /*=T*/> querySelectorAll/*<T extends Element>*/(String selectors) =>
new _FrozenElementList/*<T>*/._wrap(_querySelectorAll(selectors));