+sub has_user
+{
+ my $self = shift;
+ return $self->_haslist('users', shift);
+}
+
+sub has_node
+{
+ my $self = shift;
+ return $self->_haslist('nodes', shift);
+}
+
+sub has_parent
+{
+ my $self = shift;
+ return $self->_haslist('parent', shift);
+}
+
+