linesEquals(layout) {
        if (!this.scrollEquals(layout)) {
            return false;
        }
        const tmp = this._renderedLines._get();
        const lines = tmp.lines;
        for (let i = 0, len = lines.length; i < len; i++) {
            if (lines[i].dy === -1) {
                // This line is invalid
                return false;
            }
        }
        return true;
    }
Check if the current RenderData matches accurately the new desired layout and no painting is needed.