Complete the following procedure to compile and run this example:
javac ExternExampleOriginalClass.java
java ExternExampleOriginalClass -s
javac ExternExampleEvolvedClass.java
java ExternExampleEvolvedClass -d
This procedure tests compatibility in one direction only. To test bidirectional compatibility, perform the same procedure in the other direction (in steps 1-4, replace the original class name with the evolved class name, and vice versa).