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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 set_write_buffer_limits(self, high=None, low=None):
 """Set the low and high watermark for the write buffer."""

        if high is None:
            high = self.write_buffer_size
        if low is None:
            low = high // 2
        if low > high:
            low = high
        self._write_buffer_high = high
        self._write_buffer_low = low