Element#down([expression[, index = 0]]) → Element
Element#down([index = 0]) → Element

• expression (String) – A CSS selector.

Returns element's first descendant (or the Nth descendant, if index is specified) that matches expression. If no expression is provided, all descendants are considered. If no descendant matches these criteria, undefined is returned.

This method can be called either as an instance method or as a generic method. If calling as a generic, pass the instance in as the first argument.