Index: TECH/ListUtils.cls.xml
===================================================================
diff -u -r1563 -r1567
--- TECH/ListUtils.cls.xml	(.../ListUtils.cls.xml)	(revision 1563)
+++ TECH/ListUtils.cls.xml	(.../ListUtils.cls.xml)	(revision 1567)
@@ -453,14 +453,16 @@
 <Implementation><![CDATA[
 	#dim IsMaximum As %Boolean = (##class(TECH.enu.Extrema).Maximum() = Extrema)
 	#dim Extreme As %CacheString = ""
-	If Lijst.Count() > 0 {
-		Set Extreme = Lijst.GetAt(1)
-		#dim i As TECH.Integer
-		For i = 2:1:Lijst.Count() {
-			#dim HulpWaarde As %CacheString = Lijst.GetAt(i)
-			If (..ExtremaComparatorValidator(HulpWaarde,Extreme, Comparator, IsMaximum)) {
-				Set Extreme = HulpWaarde	
-			}
+	If (Lijst.Count() = 0)  {
+		Do ##class(TECH.ExceptionHandler).Throw(##class(TECH.Exceptions.InvalidInputException).%New("GeefExtrema: Lijst heeft geen items."))
+	}
+	
+	Set Extreme = Lijst.GetAt(1)
+	#dim i As TECH.Integer
+	For i = 2:1:Lijst.Count() {
+		#dim HulpWaarde As %CacheString = Lijst.GetAt(i)
+		If (..ExtremaComparatorValidator(HulpWaarde,Extreme, Comparator, IsMaximum)) {
+			Set Extreme = HulpWaarde	
 		}
 	}
 	Quit Extreme