Hook that prevents a second root from being created.
[Source]
# File lib/sequel/plugins/tree.rb, line 146 146: def before_save 147: if possible_root? && (root = model.root) && pk != root.pk 148: raise TreeMultipleRootError, "there is already a root #{model.name} defined" 149: end 150: super 151: end
[Validate]