    # File lib/nokogiri/xml/node.rb, line 293
          def add_previous_sibling node_or_tags
            node_or_tags = coerce(node_or_tags)
            if node_or_tags.is_a?(XML::NodeSet)
              if text?
                pivot = Nokogiri::XML::Node.new 'dummy', document
                add_previous_sibling_node pivot
              else
                pivot = self
              end
              node_or_tags.each { |n| pivot.send :add_previous_sibling_node, n }
              pivot.unlink if text?
            else
              add_previous_sibling_node node_or_tags
            end
            node_or_tags
          end