class TaskQueueError(Exception):
    """Base exception for task queue errors"""

    pass


class TaskAlreadyExistsError(TaskQueueError):
    """Raised when attempting to add a task with an ID that already exists"""

    pass


class TaskNotFoundError(TaskQueueError):
    """Raised when attempting to access a non-existent task"""

    pass


class QueueNotFoundError(TaskQueueError):
    """Raised when attempting to access a non-existent queue"""

    pass


class QueueProcessorError(TaskQueueError):
    """Raised when the queue processor encounters an error"""

    pass
