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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 exists(self, pattern, **match_kwargs):
 """Check if image exists in screen Returns: If exists, return FindPoint, or return None if result.confidence < self.image_match_threshold """

        ret = self.match(pattern, **match_kwargs)
        if ret is None:
            return None
        if not ret.matched:
            return None
        return ret