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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 write_file(self, filename, **kwargs):
 """ Writes POSCAR to a file. The supported kwargs are the same as those for the Poscar.get_string method and are passed through directly. """

        with zopen(filename, "wt") as f:
            f.write(self.get_string(**kwargs))