| filestream root |
	Cursor wait
		showWhile: [
			root := Smalltalk at: #ProtoObject ifAbsent: [Smalltalk at: #Object ifAbsent: [^ self error: 'nothing']].
			[filestream := FileStream fileNamed: 'SqueakClasses ' , Smalltalk version , '.txt'.
			Smalltalk timeStamp: filestream.
			filestream cr.
			filestream tab; nextPutAll: 'Answer a description containing the names and instance variable names 
        of all of the subclasses of ''' , root printString , '''.'.
			filestream nextPutAll: root printHierarchy]
				ifError: [:err :rcvr | filestream close]].
	filestream