Added msg.isMentioned

src/Structures/Message.js

@@ -37,6 +37,15 @@ class Message{
 				this.mentions.add(client.internal.users.add(new User(mention, client)));
 		});
 	}
+	
+	isMentioned(user){
+		user = this.client.internal.resolver.resolveUser(user);
+		if (user) {
+			return this.mentions.has(user);
+		} else {
+			return false;
+		}
+	}
 
 	toString(){
 		return this.content;