The Formik source code is written in TypeScript, so you can rest easy that Formik's
types will always be up-to-date. As a mental model, Formik's type signatures are very
similar to React Router 4's <Route>.
15// Aside: You may see InjectedFormikProps<OtherProps, FormValues> instead of what comes below in older code.. InjectedFormikProps was artifact of when Formik only exported a HoC. It is also less flexible as it MUST wrap all props (it passes them through).