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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 filter_genes(self, gene_names : Iterable[str]):
 """Filter the expression matrix against a set of genes. Parameters gene_names: list of str The genome to filter the genes against. Returns ------- ExpMatrix The filtered expression matrix. """


        filt = self.loc[self.index & gene_names]
        return filt