How to use the react-map-gl.supported function in react-map-gl

test('MapGL call onLoad when provided', t => {
  const reactContainer = document.createElement('div');
  document.body.appendChild(reactContainer);

  function onLoad(...args) {
    t.equal(args.length, 0, 'onLoad does not expose the map object.');
    t.end();
  }

  const props = {...defaultProps, onLoad};
  ReactDOM.render(, reactContainer);

  if (!MapGL.supported()) {
    t.end();
  }

});

() => {
      if (!ReactMapGL.supported()) {
        setIsSupported(false);
        onMapError('WebGL not supported');
      }
    },
    [],