Hi, I got this error while compilation if any one of (1) or (2) were uncommented saying that reference to method is ambiguous both method method (java.io.IoException) in testing and method method(java.lang.Integer) in testing match tc.method(null); But, i am surprised how this java.io.IoException and java.lang.Integer are related . can anybody please explain me ? thanks in advance. public class testing { ...