Just about every time I set up a new `Context.Provider`, I end up accidentally specifying a `values` prop rather than `value`.  While it's a minor error, generally I build the container in which the provider resides and commit it to the code base before I ever use it.  It's only later when I go to use it that I realize I did it again.  Since the `Context.Provider` seems pretty much useless without a `value` prop specified, I'd love it if there was a prop error if it is missing... especially if another prop is defined on the `Context.Provider` instead.
static childContextTypes = {
          legacyValue: () => {},
        };
        state = {legacyValue: 1};
        getChildContext() {
          return {legacyValue: this.state.legacyValue};
        }
        render() {
          Scheduler.unstable_yieldValue('LegacyProvider');
          return this.props.children;
        }
      }
      class App extends React.Component {