--- a/SequenceableCollection.st	Mon May 14 22:25:09 2018 +0200
+++ b/SequenceableCollection.st	Tue May 15 13:04:16 2018 +0200
@@ -450,6 +450,7 @@
     ^ self == SequenceableCollection
 ! !
 
+
 !SequenceableCollection methodsFor:'Compatibility-Squeak'!
 
 allButFirst
@@ -786,6 +787,7 @@
     ^ self replaceFrom:start to:stop with:anArray startingAt:repStart
 ! !
 
+
 !SequenceableCollection methodsFor:'accessing'!
 
 after:anObject
@@ -7263,6 +7265,7 @@
     "Created: 14.2.1997 / 16:13:03 / cg"
 ! !
 
+
 !SequenceableCollection methodsFor:'searching'!
 
 detect:aBlock startingAt:startIndex
@@ -10857,8 +10860,8 @@
 includesKey:anIndex
     "return true, if anIndex is a valid key.
      NOTICE: in ST-80, this message is only defined for Dictionaries,
-	     however, having a common protocol with indexed collections
-	     often simplifies things."
+             however, having a common protocol with indexed collections
+             often simplifies things."
 
     anIndex isInteger ifFalse:[^ false].
     ^ (anIndex >= 1) and:[anIndex <= self size]
@@ -10866,6 +10869,7 @@
     "
      #(1 2 3) includesKey:4
      #(1 2 3) includesKey:3
+     #(1 2 3) includesKey:0
     "
 ! !