The purpose of AccessNode is to denote a node which can have declaration modifiers, eg abstract, final, public, etc. Some nodes implement it just to get the "final" modifier:

• ASTFormalParameter
• ASTResource (relates to [java] AST inconsistencies around FormalParameter #998)
• ASTLocalVariableDeclaration

ASTLambdaExpression implements it for nothing, due to an implementation error: AbstractMethodLikeNode extends AbstractJavaAccessNode...

1. I think all of these should stop implementing the interface in 7.0.0. We could have a separate base class for nodes that can be final, or implement it ad-hoc with a boolean since FormalParameter is a TypeNode and so we'd have to have several base classes. The amount of duplication seems acceptable
2. The setters should be removed from the interface. They're only used by the parser, and could be package-private