first iteration of __isub__ method in RankingStat

gstlal-inspiral/python/stats/horizonhistory.py

@@ -254,14 +254,6 @@ class NearestLeafTree(object):
 			self[x] = val
 		return self
 
-	def __isub__(self, other):
-		"""
-		For every (key, value) pair in other, remove the entry from self.
-		"""
-		for x, val in other.tree:
-			self[x] = val
-		return self
-
 	def __isub__(self, other):
 		for key, val in other.items():
 			if key in self: