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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 run_step(self, rewriter):
 """Do the file in to out rewrite. Doesn't do anything more crazy than call files_in_to_out on the rewriter. Args: rewriter: pypyr.filesystem.FileRewriter instance. """

        assert rewriter, ("FileRewriter instance required to run "
                          "FileInRewriterStep.")
        rewriter.files_in_to_out(in_path=self.path_in, out_path=self.path_out)