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    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
    *
    * This code is free software; you can redistribute it and/or modify it
    * under the terms of the GNU General Public License version 2 only, as
    * published by the Free Software Foundation.  Oracle designates this
    * particular file as subject to the "Classpath" exception as provided
    * by Oracle in the LICENSE file that accompanied this code.
   *
   * This code is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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  package eu.simuline.util;
  
  import java.io.Serializable;
  import java.io.IOException;
  import java.io.InvalidObjectException;
  import java.io.ObjectInputStream;
  import java.io.ObjectStreamException;
  
  /**
   * This class is inspired by {@link java.lang.Enum} 
   * and is intended as common base class of classes we shall call 'soft enums'. 
   * While soft enums are ordinary classes and lack all support 
   * special to enumeration types, 
   * they are also not subject to the restrictions that come with them. 
   * <p>
   * It is the programmer who is responsible for implementing soft enums 
   * in a proper way. 
   * <p>
   * As enumeration types 
   * are implicitely final subclasses of {@link java.lang.Enum}, 
   * 'soft enums' are derived from {@link SoftEnum} 
   * and shall be final except if constants overwrite methods. 
   * A 'soft enum' shall have no instances 
   * other than those defined by its enum constants. 
  
   *
   * More information about enums, including descriptions of the
   * implicitly declared methods synthesized by the compiler, can be
   * found in section 8.9 of
   * <cite>The Java&trade; Language Specification</cite>.
   *
   * <p> Note that when using an enumeration type as the type of a set
   * or as the type of the keys in a map, specialized and efficient
   * {@linkplain java.util.EnumSet set} and {@linkplain
   * java.util.EnumMap map} implementations are available.
   *
   * @param <E> The enum type subclass
   * @author  Josh Bloch
   * @author  Neal Gafter
   * @see     Class#getEnumConstants()
   * @see     java.util.EnumSet
   * @see     java.util.EnumMap
   * @since   1.5
   */
  public abstract class SoftEnum<E extends SoftEnum<E>>
      implements Comparable<E>, Serializable {
  
      private static final long serialVersionUID = -2479143000061671589L;
  
      /**
       * The name of this enum constant, as declared in the enum declaration.
       * Most programmers should use the {@link #toString} method rather than
       * accessing this field.
       */
      private final String name;
  
      /**
       * Returns the name of this enum constant, exactly as declared in its
       * enum declaration.
       *
       * <b>Most programmers should use the {@link #toString} method in
       * preference to this one, as the toString method may return
       * a more user-friendly name.</b>  This method is designed primarily for
       * use in specialized situations where correctness depends on getting the
       * exact name, which will not vary from release to release.
       *
       * @return the name of this enum constant
       */
      public final String name() {
          return name;
      }
  
      /**
       * The ordinal of this enumeration constant (its position
      * in the enum declaration, where the initial constant is assigned
      * an ordinal of zero).
      *
      * Most programmers will have no use for this field.  It is designed
      * for use by sophisticated enum-based data structures, such as
      * {@link java.util.EnumSet} and {@link java.util.EnumMap}.
      */
     private final int ordinal;
 
     /**
      * Returns the ordinal of this enumeration constant (its position
      * in its enum declaration, where the initial constant is assigned
      * an ordinal of zero).
      *
      * Most programmers will have no use for this method.  It is
      * designed for use by sophisticated enum-based data structures, such
      * as {@link java.util.EnumSet} and {@link java.util.EnumMap}.
      *
      * @return the ordinal of this enumeration constant
      */
     public final int ordinal() {
         return ordinal;
     }
 
     /**
      * Sole constructor.  Programmers cannot invoke this constructor.
      * It is for use by code emitted by the compiler in response to
      * enum type declarations.
      *
      * @param name - The name of this enum constant, which is the identifier
      *               used to declare it.
      * @param ordinal - The ordinal of this enumeration constant (its position
      *         in the enum declaration, where the initial constant is assigned
      *         an ordinal of zero).
      */
     protected SoftEnum(String name, int ordinal) {
         this.name = name;
         this.ordinal = ordinal;
     }
 
     /**
      * Returns the name of this enum constant, as contained in the
      * declaration.  This method may be overridden, though it typically
      * isn't necessary or desirable.  An enum type should override this
      * method when a more "programmer-friendly" string form exists.
      *
      * @return the name of this enum constant
      */
     public final String toString() {
         return name;
     }
 
     /**
      * Returns true if the specified object is equal to this
      * enum constant.
      *
      * @param other the object to be compared for equality with this object.
      * @return  true if the specified object is equal to this
      *          enum constant.
      */
     public final boolean equals(Object other) {
         return this == other;
     }
 
     /**
      * Returns a hash code for this enum constant.
      *
      * @return a hash code for this enum constant.
      */
     public final int hashCode() {
         return super.hashCode();
     }
 
     /**
      * Throws CloneNotSupportedException.  This guarantees that enums
      * are never cloned, which is necessary to preserve their "singleton"
      * status.
      *
      * @return (never returns)
      */
     public final SoftEnum<E> clone() throws CloneNotSupportedException {
         throw new CloneNotSupportedException();
     }
 
     /**
      * Compares this enum with the specified object for order.  Returns a
      * negative integer, zero, or a positive integer as this object is less
      * than, equal to, or greater than the specified object.
      *
      * Enum constants are only comparable to other enum constants of the
      * same enum type.  The natural order implemented by this
      * method is the order in which the constants are declared.
      */
     public final int compareTo(E obj) {
         SoftEnum<E> other = obj;
         SoftEnum<E> self = this;
         if (self.getClass()          != other.getClass() && // optimization
             self.getDeclaringClass() != other.getDeclaringClass()) {
             throw new ClassCastException();
 	}
         return self.ordinal - other.ordinal;
     }
 
     /**
      * Returns the Class object corresponding to this enum constant's
      * enum type.  Two enum constants e1 and  e2 are of the
      * same enum type if and only if
      *   e1.getDeclaringClass() == e2.getDeclaringClass().
      * (The value returned by this method may differ from the one returned
      * by the {@link Object#getClass} method for enum constants with
      * constant-specific class bodies.)
      *
      * @return the Class object corresponding to this enum constant's
      *     enum type
      */
     public final Class<?> getDeclaringClass() {
         Class<?> clazz = getClass();
         Class<?> zuper = clazz.getSuperclass();
         return (zuper == Enum.class) ? clazz : zuper;
     }
 
     /*
      * Returns the enum constant of the specified enum type with the
      * specified name.  The name must match exactly an identifier used
      * to declare an enum constant in this type.  (Extraneous whitespace
      * characters are not permitted.)
      *
      * <p>Note that for a particular enum type {@code T}, the
      * implicitly declared {@code public static T valueOf(String)}
      * method on that enum may be used instead of this method to map
      * from a name to the corresponding enum constant.  All the
      * constants of an enum type can be obtained by calling the
      * implicit {@code public static T[] values()} method of that
      * type.
      *
      * @param <T> The enum type whose constant is to be returned
      * @param enumType the {@code Class} object of the enum type from which
      *      to return a constant
      * @param name the name of the constant to return
      * @return the enum constant of the specified enum type with the
      *      specified name
      * @throws IllegalArgumentException if the specified enum type has
      *         no constant with the specified name, or the specified
      *         class object does not represent an enum type
      * @throws NullPointerException if {@code enumType} or {@code name}
      *         is null
      * @since 1.5
      */
     // public static <T extends Enum<T>> T valueOf(Class<T> enumType,
     //                                             String name) {
     //     T result = enumType.enumConstantDirectory().get(name);
     //     if (result != null)
     //         return result;
     //     if (name == null)
     //         throw new NullPointerException("Name is null");
     //     throw new IllegalArgumentException(
     //         "No enum constant " + enumType.getCanonicalName() + "." + name);
     // }
 
     // /**
     //  * enum classes cannot have finalize methods.
     //  */
     // protected final void finalize() { // NOPMD
     // }
 
     /**
      * Prevent default deserialization.
      */
     @SuppressWarnings("PMD.UnusedFormalParameter")
     private void readObject(ObjectInputStream stream) 
 	throws IOException, ClassNotFoundException {
         throw new InvalidObjectException("can't deserialize enum");
     }
 
     @SuppressWarnings("PMD.UnusedPrivateMethod")
     private void readObjectNoData() throws ObjectStreamException {
         throw new InvalidObjectException("can't deserialize enum");
     }
 }