package com.atlassian.activeobjects.external;
   
   public final class ModelVersion implements Comparable<ModelVersion> {
       private final int version;
   
       private ModelVersion(int version) {
           this.version = version;
       }
   
      @Override
      public int compareTo(ModelVersion mv) {
          return version - mv.version;
      }
  
      public boolean isOlderThan(ModelVersion mv) {
          return compareTo(mv) < 0;
      }
  
      public boolean isNewerThan(ModelVersion mv) {
          return compareTo(mv) > 0;
      }
  
      public boolean isSame(ModelVersion mv) {
          return compareTo(mv) == 0;
      }
  
      @Override
      public String toString() {
          return String.valueOf(version);
      }
  
      public static ModelVersion valueOf(String s) {
          return s == null ? zero() : new ModelVersion(Integer.valueOf(s));
      }
  
      private static ModelVersion zero() {
          return new ModelVersion(0);
      }
  }