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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_submission_and_student(uuid, read_replica=False):
 """ Retrieve a submission by its unique identifier, including the associated student item. Args: uuid (str):
 the unique identifier of the submission. Kwargs: read_replica (bool):
 If true, attempt to use the read replica database. If no read replica is available, use the default database. Returns: Serialized Submission model (dict) containing a serialized StudentItem model Raises: SubmissionNotFoundError: Raised if the submission does not exist. SubmissionRequestError: Raised if the search parameter is not a string. SubmissionInternalError: Raised for unknown errors. """

    # This may raise API exceptions
    submission = get_submission(uuid, read_replica=read_replica)

    # Retrieve the student item from the cache
    cache_key = "submissions.student_item.{}".format(submission['student_item'])
    try:
        cached_student_item = cache.get(cache_key)
    except Exception:
        # The cache backend could raise an exception
        # (for example, memcache keys that contain spaces)
        logger.exception("Error occurred while retrieving student item from the cache")
        cached_student_item = None

    if cached_student_item is not None:
        submission['student_item'] = cached_student_item
    else:
        # There is probably a more idiomatic way to do this using the Django REST framework
        try:
            student_item_qs = StudentItem.objects
            if read_replica:
                student_item_qs = _use_read_replica(student_item_qs)

            student_item = student_item_qs.get(id=submission['student_item'])
            submission['student_item'] = StudentItemSerializer(student_item).data
            cache.set(cache_key, submission['student_item'])
        except Exception as ex:
            err_msg = "Could not get submission due to error: {}".format(ex)
            logger.exception(err_msg)
            raise SubmissionInternalError(err_msg)

    return submission