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.
return null;
    }
    const renderer = ReactTestRenderer.create(<Empty />);
    expect(renderer.toJSON()).toEqual(null);
  });
  it('exposes a type flag', () => {
    function Link() {
      return <a role="link" />;
    }
    const renderer = ReactTestRenderer.create(<Link />);
    const object = renderer.toJSON();
    expect(object.$$typeof).toBe(Symbol.for('react.test.json'));
    
    for (const key in object) {
      if (object.hasOwnProperty(key)) {
        expect(key).not.toBe('$$typeof');
      }
    }
  });
  it('can render a composite component', () => {
    class Component extends React.Component {