title: class.isAssignableFrom() send false when not the same package
body: <p>I'm using isAssignableFrom() Class method to determine if a class from an other application implements an interface or not. Thus I have the same interface in both "application" but not in the same package. And the method returns false when the package of both interfaces is not the same, but true otherwise.</p>
  
  <p>Is that a normal behaviour ?</p>