human
Solve the following python programming problem given the following code:
def createMenuItems(self, invocation) : 
    def addRequestsToTab(e) : 
        for messageInfo in messages : 
            messageIndex = self._db.createNewMessage (self._callbacks.saveBuffersToTempFiles (messageInfo), self._helpers.analyzeRequest (messageInfo).getUrl ()) 
self._messageTable.redrawTable () 
ret = [] 
    messages = invocation.getSelectedMessages () 
    valid = True 
    if (invocation.getInvocationContext () == invocation.CONTEXT_TARGET_SITE_MAP_TREE) : 
        for selected in messages : 
            if (not selected.getResponse ()) : 
                valid = False 
if valid : 
        menuItem = JMenuItem ('Send request(s) to AuthMatrix') 
        menuItem.addActionListener (<MASK>) 
        ret.append (menuItem) 
return ret 
    
    Given the code above, what is a proper replacement for <MASK>? Choose among: self, ret, menuItem, valid, messages, invocation, selected
assistant
#Here is a proper replacement for <MASK>.
def addRequestsToTab(