Create a small custom nested Visual Composer element (2)

For the wordpress theme I'm developing I need custom visual composer elements. While my custom elements work in general I have issues to get the nested elements working. Something like [single_img width="500"] or [text color="red"]My Text[/text] works perfectly. What's not working is something like: [container cols="2"] [headline color="red"]My Headline[/headline] [text color="blue" class="important"]Any text that is visible[/text] [/container] and to "translate it to something like: <div class="cols-2"> <h1 style="color: red;">My Headline</h1> <span class="important" style="color: blue;">Any text that is visible</span> </div> It's your job to make it work. I would provide my current theme where the VC elements work. You need to add one demo wrapper element and two basic "child" elements that sit inside of the wrapper. All have just one or two demo values to showcase how to pass the code from the vc_map() to the shortcode. The Child Elements also have a "content" (type: textarea_html) for demonstration. Use the Keyword VC in your bid to show that you've read this description and know what you're bidding for. Please bid a real price and time. I don't accept changes of the price you bid!