':param callable callback: user\'s callback, having the signature
callback(channel, method, properties, body), where
channel: pika.Channel
method: pika.spec.Basic.Return
properties: pika.spec.BasicProperties
body: str, unicode, or bytes (python 3.x)
:param pika.Channel channel:
:param pika.spec.Basic.Return method:
:param pika.spec.BasicProperties properties:
:param body: str, unicode, or bytes (python 3.x)'

def __init__(self, callback, channel, method, properties, body):

    self.callback = callback
    self.channel = channel
    self.method = method
    self.properties = properties
    self.body = body
