OverlayEntry _buildOverlayFeedback(BuildContext context, String tituloEvento) {
      return OverlayEntry(
        builder: (context) => Material(
          child: Container(
            width: double.infinity,
            height: double.infinity,
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: <Widget>[
                Column(
                  children: <Widget>[
                    ListTile(
                      leading: Icon(Icons.sentiment_dissatisfied),
                      title: Text('No me ha gustado'),
                      onTap: () {
                            // how to close myself????
                      },
                    ),
                    ListTile(
                        leading: Icon(Icons.sentiment_very_satisfied),
                        title: Text('Muy bien'),
                        onTap: () {}),
                  ],
                ),
              ],
            ),
          ),
        ),
      );
    }

OverlayEntry _buildOverlayFeedback(BuildContext context, String tituloEvento) {
        OverlayEntry entry;
        entry = OverlayEntry(
          builder: (context) => Material(
            child: Container(
              width: double.infinity,
              height: double.infinity,
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: <Widget>[
                  Column(
                    children: <Widget>[
                      ListTile(
                        leading: Icon(Icons.sentiment_dissatisfied),
                        title: Text('No me ha gustado'),
                        onTap: () {
                          entry.remove();
                        },
                      ),
                      ListTile(
                          leading: Icon(Icons.sentiment_very_satisfied),
                          title: Text('Muy bien'),
                          onTap: () {}),
                    ],
                  ),
                ],
              ),
            ),
          ),
        );
        return entry;
      }