title: How to get all classes which implement specified interface
body: <p>How to get all classes which implement specified interface in Android?
  I think Classloader and Class classes should be used somehow..</p>
  
  <p>Walking all loaded by classloader classes and checking, if it implements specified interface, is not good idea i suppose.</p>
  
  <p>I've found similar question and perfect answers here: <a href="https://stackoverflow.com/questions/435890/find-java-classes-implementing-an-interface">Find Java classes implementing an interface</a>.</p>
  
  <p>BUT Dalvik has some restrictions and i wonder which method is available on Android.
  Thanks.</p>