"Unfortunately, Pharo is too smart, and signals an error :)"
maxInstVars := 254. "I guess 8 bits are dedicated in the bytecodes to the offset"
instVarNames := String streamContents: [ :s | (1 to: maxInstVars + 1)
	do: [ :e | | validVarName |
		validVarName := e asWords select: [ :c | c isLetter ].
		s nextPutAll: validVarName ]
	separatedBy: [ s nextPut: Character space ] ].
Object subclass: #MyClass
	instanceVariableNames: instVarNames
	classVariableNames: ''
	poolDictionaries: ''
	category: 'MyCategory'