'Prepare message data.'

def prepare_message(self, body, priority=None, content_type=None, content_encoding=None, headers=None, properties=None):

    properties = (properties or {})
    properties.setdefault(u'delivery_info', {})
    properties.setdefault(u'priority', (priority or self.default_priority))
    return {u'body': body, u'content-encoding': content_encoding, u'content-type': content_type, u'headers': (headers or {}), u'properties': (properties or {})}
