inject

# File lib/rexml/element.rb, line 902
    def inject( xpath=nil, initial=nil, &block )
      first = true
      XPath::each( @element, xpath ) {|e|
        if (e.kind_of? Element)
          if (first and initial == nil)
            initial = e
            first = false
          else
            initial = yield( initial, e ) if e.kind_of? Element
          end
        end
      }
      initial
    end