function buildMatchedCascades(node, matchedStyles)
        {
            if (!matchedStyles || node !== this.node())
                return null;

            return {
                matched: this._buildMatchedRulesSectionCascade(matchedStyles),
                pseudo: this._buildPseudoCascades(matchedStyles)
            };
        }
@param {!WebInspector.DOMNode} node
@param {?WebInspector.CSSStyleModel.MatchedStyleResult} matchedStyles
@return {?{matched: !WebInspector.SectionCascade, pseudo: !Map.<number, !WebInspector.SectionCascade>}}
@this {WebInspector.StylesSidebarPane}