Index: spacemap.py
==================================================================
--- spacemap.py
+++ spacemap.py
@@ -52,13 +52,14 @@
 			if pair[0] == None:
 				break
 			pairs += pair,
 		last_pair = self.__bottom
 		for pair in pairs:
-			if last_pair in self.__pairs and pair[0] <= self.__pairs[last_pair] and pair[1] > self.__pairs[last_pair]:
-				self.__pairs[last_pair] = pair[1]
-				del(self.__pairs[pair[0]])
+			if last_pair in self.__pairs and pair[0] <= self.__pairs[last_pair]:
+				if pair[1] > self.__pairs[last_pair]:
+					self.__pairs[last_pair] = pair[1]
+					del(self.__pairs[pair[0]])
 			else:
 				last_pair = pair[0]
 		self.clear()
 
 	def rewind(self):
@@ -334,5 +335,12 @@
 		self.clear()
 		return(end)
 
 	def __len__(self):
 		return(len(self.__pairs))
+
+	def max(self):
+		result = None
+		for last in self.__pairs.itervalues():
+			if result == None or result < last:
+				result = last
+		return(result)