human
Solve the following python programming problem given the following code:
def addCallback(self, service, nodeIdentifier, callback) : 
    def interaction(cursor) : 
        cursor.execute ('SELECT 1 as bool FROM callbacks
                              WHERE service=%s and node=%s and uri=%s', (service.full (), nodeIdentifier, callback)) 
        if cursor.fetchall () : 
            return 
cursor.execute ('INSERT INTO callbacks
                              (service, node, uri) VALUES
                              (%s, %s, %s)', (service.full (), nodeIdentifier, callback)) 
return self.dbpool.runInteraction (nodeIdentifier) 

    
    

    Fix the buggy line: return self.dbpool.runInteraction (nodeIdentifier)
assistant
#Here is Python code to fix the buggy line: return self.

return self.dbpool.runInteraction (def interaction()