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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 ruamelindex(self, strictindex):
 """ Get the ruamel equivalent of a strict parsed index. E.g. 0 -> 0, 1 -> 2, parsed-via-slugify -> Parsed via slugify """

        return (
            self.key_association.get(strictindex, strictindex)
            if self.is_mapping()
            else strictindex
        )