sub send {
    my $self = shift;
    my $meth = shift;

    if ( ref($self) ) {    ### instance method:
        my ( $method, @args );
        if (@_) {          ### args; use them just this once
            $method = 'send_by_' . $meth;
            @args   = @_;
        } else {           ### no args; use defaults
            $method = "send_by_$Sender";
            @args   = @{ $SenderArgs{$Sender} || [] };
        }
        $self->verify_data if $AUTO_VERIFY;    ### prevents missing parts!
        Carp::croak "Unknown send method '$meth'" unless $self->can($method);
        return $self->$method(@args);
    } else {                                   ### class method:
        if (@_) {
            my @old = ( $Sender, @{ $SenderArgs{$Sender} } );
            $Sender              = $meth;
            $SenderArgs{$Sender} = [@_];       ### remaining args
            return @old;
        } else {
            Carp::croak "class method send must have HOW... arguments\n";
        }
    }
}