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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 fixed_indexer(self):
 """ indexer for fixed status Returns ------- fixed_indexer : pandas.Series """

        #isfixed = self.pst.parameter_data.partrans == "fixed"
        isfixed = self.pst.parameter_data.partrans.\
            apply(lambda x : x in ["fixed","tied"])
        return isfixed.values