Typesafe enums with private access - strange or useful?

Question

Given the class listed at the bottom, you'll notice that it's possible to specify a typesafe enum, and restrict that enum to clients in such a way that - and here's the strange part - the constant class is not exported in the api, despite the fact that it's required as an argument to the constructor.
In other words you can legally state:
MyClass myClass = new MyClass(MyClass.PLAIN);but not:
MyClass.Constant constant = MyClass.PLAIN;
MyClass myClass = new MyClass(constant);Anyone else noticed this? (Still coming to terms with the meaning of it).
/k1
Example code:
* Type safety demo
package blah;
* Demo class showing the use of inaccessible constants
public class MyClass {
     /** My first constant */
     public static final Constant FIRST;
     /** My second constant */
     public static final Constant SECOND;
     /* The instance constant field */
     private Constant constant;
     /* static initialiser for the constants */
     static {
          FIRST = new Constant("First");
          FANCY = new Constant("Second");
      * @param constant The constant spec
     public MyClass(Constant constant) {
          super();
          this.constant = constant;
     private static class Constant {
          private String name;
           * @param name The name of my constant
          public Constant(String name) {
               this.name = name;
}

Answer 1

And indeed outside the package...
package blah.test;
import blah.*;
public class Driver {
      * Main method for the sake of demonstration...
     public static void main(String[] args) {
          Object[] constants = MyClass.VALUES;
          for (int i = 0; i < constants.length; i++) {
               System.out.println(constants);
               MyClass myClass = new MyClass(constants[i]);
               System.out.println(myClass);
...then...
* Type safety demo
package blah;
* Demo class showing the use of inaccessible constants
public class MyClass {
     /** My first constant */
     public static final Constant FIRST = new Constant("First");
     /** My second constant */
     public static final Constant SECOND = new Constant("Second");
     /** An array of the constants */
     public static final Constant[] VALUES = { FIRST, SECOND };
     /* The instance constant field */
     private Constant constant;
      * @param constant The constant spec
     public MyClass(Object constant) {
          super();
          if (constant instanceof Constant) {
               this.constant = (Constant)constant;
     private static class Constant {
          private String name;
           * @param name The name of my constant
          public Constant(String name) {
               this.name = name;
           * @return The name of the constant
          public String toString() {
               return name;