test[S8Ref] isNull

"NULL"
NULL := S8Ref null.
NULL isNil ifTrue: [ ^self error: 'NULL not found.' ].

(S8Ref current hexAddress: NULL) = #0 ifFalse: [
	^self print: 'Address must be zero'
].
(S8Ref current address: NULL) = 0 ifFalse: [
	^self print: 'Address must be zero'
].
(S8Ref current isNull: (NodeBuffer string: #hello)) ifTrue: [
	^self print: 'Wrong result from #isNull'
].