Check in Apex if Chatter is enabled or not for current Org

Check in Apex if Chatter is enabled or not for current Org : there are the easy way to find out is chatter is enabled or not for current org by finding iv "FeedItem" is exists or not in org.

Snippt

Map<String,Schema.SObjectType> globaldesc = Schema.getGlobalDescribe(); 
if(globaldesc.containsKey('FeedItem')){
   system.debug('Enabled!');
}
else{
   system.debug('Disabled!');
}