InnerBlocks renderAppender doesn't do anything

Question

I'm trying to add a custom appender to my InnerBlocks component. I followed the example here: https://github.com/WordPress/gutenberg/tree/master/packages/block-editor/src/components/inner-blocks

However, nothing changes when I use this code. Am I missing something or has this functionality just not been released yet?

Here's my code, but it's exactly the same as the example.

<InnerBlocks
  renderAppender={ () => (
    <button className="bespoke-appender" type="button">Some Special Appender</button>
  ) }
/>

Answer 1

As noted in comment, the code example works as expected in newer versions of Gutenberg as of June 2019.