def _remove_duplicates_in_list(list):
    """
    Removes duplicate elements in a list.

    :param list: A list with possibly duplicate elements.
    :type list: list

    :return: A list which elements are not duplicate.
    :rtype: list
    """

    shrinked_list = []
    for element in list:
        if element not in shrinked_list:
            shrinked_list.append(element)

    return shrinked_list