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.
state = {};
        render() {
          this.setState(() => {
            readContext(ThemeContext);
          });
          return null;
        }
      }
      ReactNoop.render(<Cls />);
      expect(() => expect(Scheduler).toFlushWithoutYielding()).toErrorDev([
        'Context can only be read while React is rendering',
        
        'Context can only be read while React is rendering',
        'Cannot update during an existing state transition',
      ]);
    });
  });
  describe('useContext', () => {
    it('warns on array.map(useContext)', () => {
      const Context = React.createContext(0);
      function Foo() {