human
Solve the following python programming problem given the following code:
@ login_and_domain_required 
@ requires_privilege_with_fallback (privileges.OUTBOUND_SMS) 
def send_to_recipients(request, domain) : 
    recipients = request.POST.get ('recipients') 
    message = request.POST.get ('message') 
    if (not recipients) : 
        messages.error (request, _ ("You didn't specify any recipients")) 
else : 
        if (not message) : 
            messages.error (request, _ ("You can't send an empty message")) 
else : 
            recipients = [x.strip () for x in recipients.split (',') if x.strip ()] 
            phone_numbers = [] 
            group_names = [] 
            usernames = [] 
            phone_numbers = [] 
            unknown_usernames = [] 
            GROUP = '[group]' 
            send_to_all_checked = False 
            for recipient in recipients : 
                if (recipient == '[send to all]') : 
                    send_to_all_checked = True 
                    phone_users = CouchUser.view ('users/phone_users_by_domain', startkey = [domain], endkey = [domain, { 
                        
}], include_docs = True) 
                    for user in phone_users : 
                        usernames.append (user.username) 
group_names = [] 
                    break 
else : 
                    if ((not send_to_all_checked) and recipient.endswith (GROUP)) : 
                        name = recipient [: (- len (GROUP))].strip () 
                        group_names.append (name) 
else : 
                        if re.match ('^\\+\\d+$', recipient) : 
                            def wrap_user_by_type(u) : 
                                return getattr (user_models, u ['doc'] ['doc_type']).wrap (u ['doc']) 
phone_users = CouchUser.view ('users/by_default_phone', keys = [recipient, recipient [1 :]], include_docs = True, wrapper = wrap_user_by_type).all () 
                            phone_users = filter ((lambda u : u.is_member_of (domain)), r) 
                            if (len (phone_users) > 0) : 
                                phone_numbers.append...

    
    

    Fix the buggy line: phone_users = filter ((lambda u : u.is_member_of (domain)), r)
assistant
#Here is Python code to fix the buggy line: phone_users = filter ((lambda u : u.

phone_users = filter ((lambda u : u.is_member_of (domain)), phone_users)