def _is_scheduling_fair(enqueued_slots, dequeued_slots):
    """
    We enqueued same number of requests for every slot.
    Assert correct order, e.g.

    >>> enqueued = ['a', 'b', 'c'] * 2
    >>> correct = ['a', 'c', 'b', 'b', 'a', 'c']
    >>> incorrect = ['a', 'a', 'b', 'c', 'c', 'b']
    >>> _is_scheduling_fair(enqueued, correct)
    True
    >>> _is_scheduling_fair(enqueued, incorrect)
    False
    """
    if len(dequeued_slots) != len(enqueued_slots):
        return False

    slots_number = len(set(enqueued_slots))
    for i in range(0, len(dequeued_slots), slots_number):
        part = dequeued_slots[i:i + slots_number]
        if len(part) != len(set(part)):
            return False

    return True