docs: public static Object calculateGuess(JCExpression expr) {
  		if (expr instanceof JCLiteral) {
  			JCLiteral lit = (JCLiteral) expr;
  			if (lit.getKind() == com.sun.source.tree.Tree.Kind.BOOLEAN_LITERAL) {
  				return ((Number) lit.value).intValue() == 0 ? false : true;
  			}
  			return lit.value;
  		}
  		
  		if (expr instanceof JCIdent || expr instanceof JCFieldAccess) {
  			String x = expr.toString();
  			if (x.endsWith(".class")) return new ClassLiteral(x.substring(0, x.length() - 6));
  			int idx = x.lastIndexOf('.');
  			if (idx > -1) x = x.substring(idx + 1);
  			return new FieldSelect(x);
  		}
  		
  		return null;
  	}