public void examineAction() {
		//System.out.println("examine "+actionToken);
        ANTLRStringStream in = new ANTLRStringStream(actionToken.getText());
        in.setLine(actionToken.getLine());
        in.setCharPositionInLine(actionToken.getCharPositionInLine());
        ActionSplitter splitter = new ActionSplitter(in, this);
		// forces eval, triggers listener methods
        node.chunks = splitter.getActionTokens();
    }
Trigger checks for various kinds of attribute expressions.
 no side-effects.
tool/src/org/antlr/v4/semantics/AttributeChecks.java