def ltree(column = :path, options: { cascade: true })
      cattr_accessor :ltree_path_column

      self.ltree_path_column = column

      if options[:cascade]
        after_update :cascade_update
        after_destroy :cascade_destroy
      end

      extend ClassMethods
      include InstanceMethods
    end
def ltree(column = :path, options: { cascade: true })
      cattr_accessor :ltree_path_column

      self.ltree_path_column = column

      if options[:cascade]
        after_update :cascade_update
        after_destroy :cascade_destroy
      end

      extend ClassMethods
      include InstanceMethods
    end
Initialzie ltree for active model

 @param column [String] ltree column name