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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 age_ratios():
 """Helper to get list of age ratio from the options dialog. :returns: List of age ratio. :rtype: list """

        # FIXME(IS) set a correct parameter container
        parameter_container = None

        youth_ratio = parameter_container.get_parameter_by_guid(
            youth_ratio_field['key']).value
        adult_ratio = parameter_container.get_parameter_by_guid(
            adult_ratio_field['key']).value
        elderly_ratio = parameter_container.get_parameter_by_guid(
            elderly_ratio_field['key']).value
        ratios = [youth_ratio, adult_ratio, elderly_ratio]

        return ratios