_init(node) {
        this._node = node;

        // Cache the refs to the collections.
        this._numFmtsNode = xmlq.findChild(this._node, "numFmts");
        this._fontsNode = xmlq.findChild(this._node, "fonts");
        this._fillsNode = xmlq.findChild(this._node, "fills");
        this._bordersNode = xmlq.findChild(this._node, "borders");
        this._cellXfsNode = xmlq.findChild(this._node, "cellXfs");

        if (!this._numFmtsNode) {
            this._numFmtsNode = {
                name: "numFmts",
                attributes: {},
                children: []
            };

            // Number formats need to be before the others.
            xmlq.insertBefore(this._node, this._numFmtsNode, this._fontsNode);
        }

        // Remove the optional counts so we don't have to keep them up to date.
        delete this._numFmtsNode.attributes.count;
        delete this._fontsNode.attributes.count;
        delete this._fillsNode.attributes.count;
        delete this._bordersNode.attributes.count;
        delete this._cellXfsNode.attributes.count;
    }
Initialize the style sheet node.
@param {{}} [node] - The node
@returns {undefined}
@private