'From Squeak3.1alpha of 7 March 2001 [latest update: #4173] on 21 August 2001 at 11:00:17 am'! "Change Set: environmentsFix-hg Date: 21 August 2001 Author: Henrik Gedenryd A small consolidation in Dictionary that prevents exceptions from crashing an image that has been converted to use Environments."! !Dictionary methodsFor: 'testing' stamp: 'squeak 8/16/2001 13:39'! includesKey: key "Answer whether the receiver has a key equal to the argument, key." ^(self at: key ifAbsent: [nil]) notNil! !