for my $Ref ( \(my$f), [], {}, ){
    print $Ref, "\n";
    bless $Ref, "XML::eXistDB::RPC"; 
    print "\t", ref $Ref, "\n";
}
__END__
SCALAR(0x9ba3ec)
        XML::eXistDB::RPC
ARRAY(0x3f8ba4)
        XML::eXistDB::RPC
HASH(0x9b9dec)
        XML::eXistDB::RPC