[Mailmunge] filter_recipient()

[postfix at ptld.com]

Im a little confused on proper usage of this callback. Manual says you 
SHOULD return a Mailmunge::Response object. When i allowed the function 
to just end by closing } it crashed mailmunge with this error:

   mailmunge-mx[135295]: NOQUEUE: Worker 1 stderr: Can't call method 
"fix_code_dsn" on an undefined value at 
/usr/local/share/perl5/Mailmunge/Filter.pm line 952, <STDIN> line 1.

So i assume "should" is actually "must" and I added "return 
Mailmunge::Response->CONTINUE();" at the end of the function and this 
prevented mailmunge from crashing. But now the part im not clear on is 
how to reject a mail message. Does this...

   if (some == condition) {
     $self->action_bounce($ctx, "Reason", 550, "5.7.1");
     return;
   }
   # Or this...
   return if $ctx->message_rejected();

...still meet the requirement for returning a response object? Or are 
you not supposed to use $self->action_* in filter_recipient()? Is the 
only acceptable return doing something like:

   return Mailmunge::Response->REJECT(message => 'Message', code => 550, 
DSN => '5.7.1');

Or can you request/set the reject separately like:

   Mailmunge::Response->CONTINUE();
   if (some == condition) {
     Mailmunge::Response->REJECT(message => 'Message', code => 550, DSN 
=> '5.7.1');
   }
   return;

In my situation i do sub-processing in nested functions called from 
inside of filter_recipient() and would decided to reject a message in 
one of these sub-functions. So i can't use return 
Mailmunge::Response->*() in these sub-functions. What is the best way to 
declare a reject from a sub-function?