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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 increase_in_list(list_to_increase, string_to_increase):
 """ Increase a item in a HTML list. :param list_to_increase: The list. :type list_to_increase: str :param string_to_increase: The value of item. :type string_to_increase: str :return: The HTML list with the item added, if the item not was contained in list. :rtype: str """


        if (bool(list_to_increase)) and (bool(string_to_increase)):
            if CommonFunctions.in_list(list_to_increase, string_to_increase):
                return list_to_increase
            return list_to_increase + ' ' + string_to_increase
        elif bool(list_to_increase):
            return list_to_increase
        return string_to_increase