Mockito mock implements a new interface

java.lang.ClassCastException: org.openqa.selenium.WebElement$$EnhancerByMockitoWithCGLIB$$400e318a cannot be cast to org.openqa.selenium.internal.Locatable  java:1145)    

Foo mock = Mockito.mock(Foo.class, withSettings().extraInterfaces(Bar.class));

http://stackoverflow.com/a/1270723