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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 getIndexedLength(self) : 		"""Returns the total length of indexed regions"""

		if self.x1 != None and self.x2 != None:
			return self.x2 - self.x1
		else :
			if len(self.children) == 0 :
				return 0
			else :
				l = self.children[0].x2 - self.children[0].x1
				for i in range(1, len(self.children)) :
					l += self.children[i].x2 - self.children[i].x1 - max(0, self.children[i-1].x2 - self.children[i].x1)
				return l