interface.py

import abc
from typing import Protocol, Optional, TypeVar

t_consumer_id = TypeVar('consumer_id', bound=str)


class Consumer(Protocol):
    """This class consumes input.
  Each consumer entry creates a dedicated channel to consume into.
  """

    @abc.abstractmethod
    def setup(self, channel: Optional[str] = None, **kwargs) -> t_consumer_id:
        """Setup the consumer."""
        raise NotImplementedError

    @abc.abstractmethod
    def consume(self, data: dict, **optional_attrs) -> None:
        """Consume input."""
        raise NotImplementedError


class Producer(Protocol):
    """This class produces output.
  
  Each producer entry publishes from a dedicated channel.
  """

    @abc.abstractmethod
    def setup(self, consumer_id: t_consumer_id, **kwargs) -> None:
        """Setup the producer."""
        raise NotImplementedError

    @abc.abstractmethod
    def get(self, **optional_attrs) -> None:
        """Returns output."""
        raise NotImplementedError