No need perform: #propertyAt:put:

[Ducasse]

setConvertedValueOf: aBinding
"Set the converted value of aBinding value in the correct property of the receiver. aBinding should be property and a raw value as written in the configuration"

(self declaredItems includes: aBinding key asSymbol)
	ifTrue: [ self setConvertedValueOfDeclaredProperty: aBinding ]
	ifFalse: [ self perform: #propertyAt:put: 
							with: aBinding key asSymbol 
							with: aBinding value ]