belongs_to :current_node, :class_name => "Node", :foreign_key => "node_id", :inverse_of => :old_nodes
has_many :old_tags, :class_name => "OldNodeTag", :foreign_key => [:node_id, :version], :inverse_of => :old_node
belongs_to :current_node, :class_name => "Node", :foreign_key => "node_id", :inverse_of => :old_nodes
has_many :old_tags, :class_name => "OldNodeTag", :foreign_key => [:node_id, :version], :inverse_of => :old_node