Static bubble chart (like tree map)

Add bubble vizualiztion with ability to drill down. Some times bubble charts are more visual than Tree map charts. In Visual gallery there is "Bubble" custom chart, but it doesn't support drill down and hierarchy. So, I decide to post idea to add bubble charts into basic (not custom) charts. For example, you can add an option to Tree map chart, so that user can choose brick (current tree map) or bubble type.