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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(self, wr_string):
 """ Write to file and flush :param wr_string: -- writable string :type wr_string: str :return: None :rtype: None """

        result = self.fd.write(wr_string)
        self.fd.flush()
        return result