public class YouCanNotChangeMe_IAmNotYours{
    public void doSomethingSpecial();
}

public interface MyInterface{
    void doSomethingSpecial();
}

public class ForeignClassWrapper implements MyInterface {
  private final YouCanNotChangeMe_IAmNotYours delegate;

  public ForeignClassWrapper(YouCanNotChangeMe_IAmNotYours delegate) {
    this.delegate = delegate;
  }

  public void doSomethingSpecial() {
    delegate.doSomethingSpecial();
  }
}