import java.util.Date; class DataFlowBug { private static boolean isNumberable(Object o) { return o instanceof Number; } public Object add(Object left, Object right) { if (left != null && right != null && (left instanceof Date || right instanceof Date)) { if (isNumberable(left)) { return ((<warning descr="Casting 'right' to 'Date' may produce 'java.lang.ClassCastException'">Date</warning>) right).getTime(); } if (isNumberable(right)) { return ((<warning descr="Casting 'left' to 'Date' may produce 'java.lang.ClassCastException'">Date</warning>) left).getTime(); } } return new Object(); } }