Example.java

package frodo;

public class Example {
  public static void main(String[] args) {
    new Test().run();
  }

  public void run() {
    System.out.println(someMethod(new RealFile("/foo")));
    System.out.println(someMethod(new RealFile("/bar")));
  }

  public String someMethod(RealFile file) {
    return "Hello " + file.getPath();
  }

  private static class RealFile {
    private final String path;

    RealFile(String path) { this.path = path; }

    public String getPath() { return path; }
    
    public String toString() {
      return "A file called " + getPath();
    }
  }
}