Fatal Error Unable get country based open events

[reddy-13]

//after connection code.
// based on zip it's working
//
$events = $m->getOpenEvents( array( 'country' => 'IN' ));

//output

Uncaught MeetupBadRequestException:

400 HTTP Error: Error bad request to https://api.meetup.com/2/open_events?country=IN&key=38607943f1a7b5e7116726c7c5b32b&
Details: Perhaps you're missing a required parameter. You can find full documentation of the api here: https://www.meetup.com/meetup_api/docs/
Problem: The API request is malformed

thrown in /home/greddyin/public_html/meetup/meetupApi/MeetupConnection.class.php on line 47