lib/ancestry/class_methods.rb
def to_node object
      if object.is_a?(self.ancestry_base_class) then object else unscoped_where{|scope| scope.find object} end
    end
def to_node object
      if object.is_a?(self.ancestry_base_class) then object else unscoped_where{|scope| scope.find object} end
    end
Fetch tree node if necessary