'Setup the example publisher object, passing in the URL we will use
to connect to RabbitMQ.
:param str amqp_url: The URL for connecting to RabbitMQ'

def __init__(self, amqp_url):

    self._connection = None
    self._channel = None
    self._deliveries = None
    self._acked = None
    self._nacked = None
    self._message_number = None
    self._stopping = False
    self._url = amqp_url
