Returns a node trace up to the <schema> item.

def getItemTrace(self):
        """Returns a node trace up to the <schema> item.
        """
        item, path, name, ref = self, [], 'name', 'ref'
        while not isinstance(item,XMLSchema) and not isinstance(item,WSDLToolsAdapter):
            attr = item.getAttribute(name)
            if not attr:
                attr = item.getAttribute(ref)
                if not attr:
                    path.append('<%s>' %(item.tag))
                else: 
                    path.append('<%s ref="%s">' %(item.tag, attr))
            else:
                path.append('<%s name="%s">' %(item.tag,attr))

            item = item._parent()
        try:
            tns = item.getTargetNamespace()
        except: 
            tns = ''
        path.append('<%s targetNamespace="%s">' %(item.tag, tns))
        path.reverse()
        return ''.join(path)