def is_array_of(obj, classinfo):
    """
    Check if obj is a list of classinfo or a tuple of classinfo or a set of classinfo
    :param obj: an object
    :param classinfo: type of class (or subclass). See isinstance() build in function for more info
    :return: flag: True or False
    """
    flag = False
    if isinstance(obj, classinfo):
        pass
    elif all(isinstance(item, classinfo) for item in obj):
        flag = True

    return flag