private final BranchProfile nullProfile = new BranchProfile();
public ReadInstanceVariableNode(RubyContext context, SourceSection sourceSection, String name, RubyNode receiver, boolean isGlobal) {
super(context, sourceSection);
this.receiver = BoxingNodeFactory.create(context, sourceSection, receiver);
readNode = new ReadHeadObjectFieldNode(name, hook);
this.isGlobal = isGlobal;
}