+sub _last_sibling_test {
+ my $this = shift();
+ my($address) = @_;
+
+ return undef
+ if !defined $this->_next_sibling_test($address);
+
+ my $nskipped = 0;
+ while (1) {
+ my $maybe = $this->_next_sibling_test($address);
+ last if !defined $maybe;
+ $nskipped++;
+ $this->log("irspy", "skipping $nskipped = '$address'");
+ $address = $maybe;
+ }
+
+ return ($address, $nskipped);
+}
+
+
+sub _next_sibling_test {
+ my $this = shift();
+ my($address) = @_;
+
+ my @components = split /:/, $address;
+ my $last = pop @components;
+ my $maybe = join(":", @components, $last+1);
+ return $maybe if $this->{tree}->select($maybe);
+ return undef;
+}
+
+