class DataFlowBug { public int add2(Object left, Object right) { if (left != null && !(left instanceof String)) { return ((<warning descr="Casting 'left' to 'String' may produce 'java.lang.ClassCastException'">String</warning>) left).length(); } if (!(right instanceof String)) { return ((<warning descr="Casting 'right' to 'String' may produce 'java.lang.ClassCastException'">String</warning>) right).length(); } return 2; } }