return type of overriding methods

Alpha.java

package legalReturnTypes.overriding;

public class Alpha {
	Alpha doStuff(char c) {
		return new Alpha();
	}
}

Beta.java

package legalReturnTypes.overriding;

public class Beta extends Alpha {
	Beta doStuff(char c) { //return type Beta is sub class of Alpha 
		return new Beta();
	}
}