text: class TransactionError(Exception):
      response = None
  
  
  class TransactionFailed(TransactionError):
      def __init__(self, response):
          self.response = response
  
      def __str__(self):
          out = "STUN transaction failed"
          if "ERROR-CODE" in self.response.attributes:
              out += " (%s - %s)" % self.response.attributes["ERROR-CODE"]
          return out
  
  
  class TransactionTimeout(TransactionError):
      def __str__(self):
          return "STUN transaction timed out"
  