code: def findByPath(self, rel, path):
          
          if((path=="") or (path=="/")):
              return(self)
          (front,dummy,rest) = path.lstrip("/").partition("/")
          for child in self.items:
              if front in child.values(rel):
                  return child.findByPath(rel, rest)
          return None
docs: Traverses children, building a path based on relation <rel>, until given path is found.