code: def get_deepest_match(self, name):
          
  
          depth = len(name)
          if depth > self.max_depth:
              depth = self.max_depth
          for i in xrange(-depth, 0):
              n = dns.name.Name(name[i:])
              if n in self:
                  return (n, self[n])
          v = self[dns.name.empty]
          return (dns.name.empty, v)
docs: Find the deepest match to I{name} in the dictionary.
  
          The deepest match is the longest name in the dictionary which is
          a superdomain of I{name}.
  
          @param name: the name
          @type name: dns.name.Name object
          @rtype: (key, value) tuple