InstantiateInterfaceExample

InstantiateInterfaceExample -- creating class instances that implement an interface.

Instances of different classes can implement the same interface.

To see this example in action:

Compile the Java source file, InstantiateInterfaceExample.java:
```
	javac InstantiateInterfaceExample.java
```
Run the class:
```
	java InstantiateInterfaceExample
```

Output:

    Hello world!
    7913