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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 fix_timestamps(self, time_ref):
 		""" 			manipulates internal time stamps such that the last run ends at time 0 		"""

		
		for k,v in self.data.items():
			for kk, vv in v.time_stamps.items():
				for kkk,vvv in vv.items():
					self.data[k].time_stamps[kk][kkk] += time_ref