public interface A {
  public void setStar(Star star)
}

public class A-Class implements A {
 public void setStar(StarImpl star)
}

public interface Star {
}

public class StarImpl implements Star {
}

public class A-Class implements A {
 public void setStar(<? extends Star> star)
}

public class A-Class implements A {
 public <T extends Star> void setStar(T star)
}