Replace `ifNil:[...]` with `isNil ifTrue:[...]`
The latter is optimized by compilers and therefore faster.
"{ Package: 'stx:goodies/petitparser/parsers/java' }"
"{ NameSpace: Smalltalk }"
PJASTNode subclass:#PJExpressionNode
instanceVariableNames:''
classVariableNames:''
poolDictionaries:''
category:'PetitJava-AST'
!
PJExpressionNode comment:'Common superclass for all expression nodes e.i. nodes that have some kind of valuse: variables, literals, method invocations, etc.'
!
!PJExpressionNode methodsFor:'visiting'!
acceptVisitor: aVisitor
aVisitor visitExpressionNode: self
! !