def object
      if instance_variable_defined?(:@object)
        @object
      else
        rdf_node = Redland.librdf_statement_get_object(rdf_statement)
        @object = rdf_node.null? ? nil : Node.new(rdf_node)
      end
    end
def object
      if instance_variable_defined?(:@object)
        @object
      else
        rdf_node = Redland.librdf_statement_get_object(rdf_statement)
        @object = rdf_node.null? ? nil : Node.new(rdf_node)
      end
    end
Object of the statement.

 @return [Node, nil]