async-worker/async-worker

class EmptyQueueException(Exception):
    """No message to get"""


class MessageError(ValueError):
    """Base for all message exceptions"""


class UndecodableMessageException(MessageError):
    """Can't decode as JSON"""


class InvalidMessageSizeException(MessageError):
    def __init__(self, message=None):
        """Message size if bigger than it should be"""
        self.message = message