You want to embed a YouTube or other `iframe` style embedded content, and you'd like it to take up the available width, and retain it's aspect ratio.
Much like the Bootstrap responsive embed helpers of old, but for react.
<ResponsiveEmbed ratio='16:9' src='https://www.youtube.com/embed/2yqz9zgoC-U' />
<ResponsiveEmbed ratio='4:3' src='https://www.youtube.com/embed/mM5_T-F1Yn4' />