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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 parseOneGame(self):
 		""" Parses one game from 'self.data'. Returns a 'GameTree' containing 			one game, or 'None' if the end of 'self.data' has been reached."""

		if self.index < self.datalen:
			match = self.reGameTreeStart.match(self.data, self.index)
			if match:
				self.index = match.end()
				return self.parseGameTree()
		return None