def has_xinclude?(doc)
     ret = false
     doc.root.namespaces.each do |ns|
       if (ns.href.casecmp(XINCLUDE_NS) == 0)
         ret = true
         break
       end
     end
     ret
   end
def has_xinclude?(doc)
     ret = false
     doc.root.namespaces.each do |ns|
       if (ns.href.casecmp(XINCLUDE_NS) == 0)
         ret = true
         break
       end
     end
     ret
   end
Check whether the document has a XInclude namespace