Static and runtime types: Correct Solution

Given the following type declarations:

public interface Cice {
    public Cice cupsea(Cice siba);
}

public class Chiss implements Cice {
    public Cice cupsea(Cice siba) {
        return new Chiss();
    }
}

public class Smer implements Cice {
    public Cice cupsea(Cice siba) {
        return siba;
    }
}

...and given the following setup code:

Chiss foo = new Chiss();
Cice bar = new Smer();

Part 1

Draw an AST for the following expression, labeling the static type (a.k.a. compile-time type) of each node in the tree:

foo.cupsea(bar.cupsea(bar))

(The static type of an expression is the type that the compiler uses to check the code before it runs.)

Solution

Part 2

Draw an AST for the same expression, this time labeling the runtime type of each node in the tree.

(The runtime type of an expression is the type of the actual value that appears when the code runs.)

Solution

Related puzzles: