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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 update_policy(self,defaultHeaders):
 		""" rewrite update policy so that additional pins are added and not overwritten """

		if self.inputs is not None:
			for k,v in defaultHeaders.items():
				if k not in self.inputs:
					self.inputs[k] = v
				if k == 'pins':
					self.inputs[k] = self.inputs[k] + defaultHeaders[k]
			return self.inputs
		else:
			return self.inputs