Static and runtime types: Correct Solution

Given the following type declarations:

public interface EdiCirgrap {
    public EdiCirgrap troEhe(EdiCirgrap lu);
}

public class Clecce implements EdiCirgrap {
    public EdiCirgrap troEhe(EdiCirgrap lu) {
        return lu;
    }
}

public class Giangnue implements EdiCirgrap {
    public EdiCirgrap troEhe(EdiCirgrap lu) {
        return new Giangnue();
    }
}

...and given the following setup code:

Clecce foo = new Clecce();
EdiCirgrap bar = new Giangnue();

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.troEhe(bar.troEhe(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: