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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, s):
 """Write string s to the stream if a whole new block is ready to be written. """

        self.buf += s
        while len(self.buf) > self.bufsize:
            self.fileobj.write(self.buf[:self.bufsize])
            self.buf = self.buf[self.bufsize:]