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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 get_time_to_merge_request_response(self, item):
 """Get the first date at which a review was made on the PR by someone other than the user who created the PR """

        review_dates = [str_to_datetime(review['created_at']) for review in item['review_comments_data']
                        if item['user']['login'] != review['user']['login']]
        if review_dates:
            return min(review_dates)
        return None