old_contents: __author__ = 'Xsank'
  
  
  class EventbusException():
      '''This is the base exception of the Eventbus.'''
      def __str__(self):
          return self.__doc__
  
  
  class EventTypeError(EventbusException):
      '''Event type is invalid!'''
  
  
  class ListenerTypeError(EventbusException):
      '''Listener type is invalid!'''
  
  
  class UnregisterError(EventbusException):
      '''No listener to unregister!'''
  
  
  class ProcessException(EventbusException):
      '''Post message but no listener related register!'''
  
  
  class InstanceException(EventbusException):
      '''The class can only be instantiated once!'''
new_contents: __author__ = 'Xsank'
  
  
  class EventbusException():
      '''This is the base exception of the Eventbus.'''
      def __str__(self):
          return self.__doc__
  
  
  class EventTypeError(EventbusException):
      '''Event type is invalid!'''
  
  
  class ListenerTypeError(EventbusException):
      '''Listener type is invalid!'''
  
  
  class UnregisterError(EventbusException):
      '''No listener to unregister!'''
  
  
  class ProcessException(EventbusException):
      '''Post message but no listener related register!'''
  
  
  class InstanceException(EventbusException):
      '''The class can only be instantiated once!'''
  
  
  class TaskFullException(EventbusException):
      '''Too many tasks to finished!'''
subject: add the task full exception