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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 to_string_with_default(value, default_value):
 """ Converts value into string or returns default when value is None. :param value: the value to convert. :param default_value: the default value. :return: string value or default when value is null. """

        result = StringConverter.to_nullable_string(value)
        return result if result != None else default_value