Sample.java

class Sample {
  
  public this someMethod() {
    // …
    return this;
  }
}

class Subtype extends Sample {};

Subtype instance = new Subtype();
Subtype result = instance.someMethod(); // Does obviously not compile

// Alternatives
// - Override someMethod() in Subtype and cast to Subtype
// - Use self referential generics Sample<T extends Sample<T>> and T someMethod() { return (T) this; }