minor edit to Copyable interface

Author: cicirello

lib/jpt2.jar

@@ -41,7 +41,7 @@
  * @version 9.23.2019
  * @since 1.0
  */
-public final class Permutation implements Serializable, Iterable<Permutation>, Copyable {
+public final class Permutation implements Serializable, Iterable<Permutation>, Copyable<Permutation> {
 
 	private static final long serialVersionUID = 1L;
 

src/org/cicirello/permutations/Permutation.java

@@ -29,13 +29,13 @@
  *
  * @author <a href=https://www.cicirello.org/ target=_top>Vincent A. Cicirello</a>, 
  * <a href=https://www.cicirello.org/ target=_top>https://www.cicirello.org/</a>
- * @version 9.23.2019
+ * @version 9.25.2019
  */
-public interface Copyable {
+public interface Copyable<T extends Copyable> {
 
 	/**
 	 * Creates an identical copy of this object.
 	 * @return an identical copy of this object.
 	 */
-	Copyable copy();
+	T copy();
 }