def check_user(user, event):
    """
    Checks whether the ``ReactionAddEvent``, ``ReactionDeleteEvent``'s user is same as the given one.
    
    Parameters
    ----------
    user : ``ClientUserBase``
        The user who should be matched.
    event : ``ReactionAddEvent``, ``ReactionDeleteEvent``
        The reaction addition or deletion event.
    """
    return (event.user is user)