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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 watch(self, limit=None, timeout=None):
 """Block method to watch the clipboard changing."""

        start_time = time.time()
        count = 0
        while not timeout or time.time() - start_time < timeout:
            new = self.read()
            if new != self.temp:
                count += 1
                self.callback(new)
                if count == limit:
                    break
            self.temp = new
            time.sleep(self.interval)