This function returns a DOMString describing the context of the start of this Range. This string consists of a list of element names and parentheses, such as: doc(body(chapter(title()para0(title()para( The left parenthesis following an element name represents a start tag, and the right parenthesis represents the end tag for the corresponding unmatched start tag. If this Range is before the opening start tag or if context checking is not relevant for the current document, a null string will be returned.