$method = $self->{server}->getcallback("data");
$self->$method();

##</code><code>##

...setcallback(
   data => $self->can("gotdata"),
   connect => $self->can("connected"),
   disconnect => $self->can("disconnect")
)
##</code><code>##

...setcallback(
   data => sub { $obj->gotdata },
   ...