old_contents: # Copyright (c) 2015 Nicolas JOUANIN
  #
  # See the file license.txt for copying permission.
  import asyncio
  from hbmqtt.mqtt.packet import MQTTPacket, MQTTFixedHeader, PacketType, MQTTVariableHeader, MQTTPayload
  from hbmqtt.codecs import int_to_bytes, read_or_raise, bytes_to_int
  from hbmqtt.errors import HBMQTTException
  from enum import Enum
  
  
  class ReturnCode(Enum):
      CONNECTION_ACCEPTED = 0x00
      UNACCEPTABLE_PROTOCOL_VERSION = 0x01
      IDENTIFIER_REJECTED = 0x02
      SERVER_UNAVAILABLE = 0x03
      BAD_USERNAME_PASSWORD = 0x04
      NOT_AUTHORIZED = 0x05
  
  
  class ConnackVariableHeader(MQTTVariableHeader):
      def __init__(self, session_parent=None, return_code=None):
          super().__init__()
          self.session_parent = session_parent
          self.return_code = return_code
  
      @classmethod
      def from_stream(cls, reader: asyncio.StreamReader, fixed_header: MQTTFixedHeader):
          data = yield from read_or_raise(reader, 2)
          session_parent = data[0] & 0x01
          return_code = ReturnCode(bytes_to_int(data[1]))
          return cls(session_parent, return_code)
  
      def to_bytes(self):
          out = b''
          # Connect acknowledge flags
          if self.session_parent:
              out += '\x01'
          else:
              out += '\x00'
          # return code
          out += int_to_bytes(self.return_code)
  
          return out
  
      def __repr__(self):
          return type(self).__name__ + '(session_parent={0}, return_code={1})'.format(hex(self.session_parent), hex(self.return_code.value))
  
  
  class ConnackPacket(MQTTPacket):
      VARIABLE_HEADER = ConnackVariableHeader
      PAYLOAD = None
  
      def __init__(self, fixed: MQTTFixedHeader=None, variable_header: ConnackVariableHeader=None, payload=None):
          if fixed is None:
              header = MQTTFixedHeader(PacketType.CONNACK, 0x00)
          else:
              if fixed.packet_type is not PacketType.CONNACK:
                  raise HBMQTTException("Invalid fixed packet type %s for ConnackPacket init" % fixed.packet_type)
              header = fixed
          super().__init__(header)
          self.variable_header = variable_header
          self.payload = None
  
new_contents: # Copyright (c) 2015 Nicolas JOUANIN
  #
  # See the file license.txt for copying permission.
  import asyncio
  from hbmqtt.mqtt.packet import MQTTPacket, MQTTFixedHeader, PacketType, MQTTVariableHeader, MQTTPayload
  from hbmqtt.codecs import int_to_bytes, read_or_raise, bytes_to_int
  from hbmqtt.errors import HBMQTTException
  from enum import Enum
  
  
  class ReturnCode(Enum):
      CONNECTION_ACCEPTED = 0x00
      UNACCEPTABLE_PROTOCOL_VERSION = 0x01
      IDENTIFIER_REJECTED = 0x02
      SERVER_UNAVAILABLE = 0x03
      BAD_USERNAME_PASSWORD = 0x04
      NOT_AUTHORIZED = 0x05
  
  
  class ConnackVariableHeader(MQTTVariableHeader):
      def __init__(self, session_parent=None, return_code=None):
          super().__init__()
          self.session_parent = session_parent
          self.return_code = return_code
  
      @classmethod
      def from_stream(cls, reader: asyncio.StreamReader, fixed_header: MQTTFixedHeader):
          data = yield from read_or_raise(reader, 2)
          session_parent = data[0] & 0x01
          return_code = ReturnCode(bytes_to_int(data[1]))
          return cls(session_parent, return_code)
  
      def to_bytes(self):
          out = b''
          # Connect acknowledge flags
          if self.session_parent:
              out += '\x01'
          else:
              out += '\x00'
          # return code
          out += int_to_bytes(self.return_code)
  
          return out
  
      def __repr__(self):
          return type(self).__name__ + '(session_parent={0}, return_code={1})'.format(hex(self.session_parent), hex(self.return_code.value))
  
  
  class ConnackPacket(MQTTPacket):
      VARIABLE_HEADER = ConnackVariableHeader
      PAYLOAD = None
  
      def __init__(self, fixed: MQTTFixedHeader=None, variable_header: ConnackVariableHeader=None, payload=None):
          if fixed is None:
              header = MQTTFixedHeader(PacketType.CONNACK, 0x00)
          else:
              if fixed.packet_type is not PacketType.CONNACK:
                  raise HBMQTTException("Invalid fixed packet type %s for ConnackPacket init" % fixed.packet_type)
              header = fixed
          super().__init__(header)
          self.variable_header = variable_header
          self.payload = None
  
      @classmethod
      def build(cls, session_parent, return_code):
          v_header = ConnackVariableHeader(session_parent, return_code)
          packet = ConnackPacket(variable_header=v_header)
          return packet
  
subject: Add build packet classmethod