MethodSignature valueGetter = new MethodSignature(Object.class, "get", new Class[]{OgnlContext.class, Object.class}, null);
MethodSignature valueSetter = new MethodSignature(void.class, "set", new Class[]{OgnlContext.class, Object.class, Object.class}, null);
MethodSignature expressionSetter = new MethodSignature(void.class, "setExpression", new Class[]{Node.class}, null);
if (!classFab.containsMethod(expressionSetter)) {
classFab.addField("_node", Node.class);
classFab.addMethod(Modifier.PUBLIC, expressionSetter, "{ _node = $1; }");
}