SmallBridge.sendMessage("msg");

SmallBridge.addMessageListener(function(source, data) {
    console.log(source); // bundle ID as String
    console.log(data); // received data as String
});

-(void) sendMessage:(NSBundle *) withData:(NSString *)data;

// source is URL of loaded document
-(BOOL) onReceiveMessage:(NSString *)source withData:(NSString *)data;

public void sendMessage(Context context, String data)

// source is URL of loaded document
public boolean onReceiveMessage(String source, String data)