package org.lsst.ccs.utilities.structs;
   
   import java.io.Serializable;
   
   /**
    * a simple tuple with two values.
    * The fist element is immutable.
    * @author bamade
    */
  // Date: 17/11/12
  
  public class Pair<K, V> implements Serializable {
      public final K x;
      public V y;
  
      public Pair(K x, V y) {
          this.x = x;
          this.y = y;
      }
  
      public K getX() {
          return x;
      }
  
      public V getY() {
          return y;
      }
  
      public void setX(V v) {
          this.y = v;
      }
  
      @Override
      public String toString() {
          return "[" + x + "," + y + "]";
      }
  
      @Override
      public boolean equals(Object o) {
          if (this == o) return true;
          if (!(o instanceof Pair)) return false;
  
          Pair pair = (Pair) o;
  
          if (!x.equals(pair.x)) return false;
          if (y != null ? !y.equals(pair.y) : pair.y != null) return false;
  
          return true;
      }
  
      @Override
      public int hashCode() {
          int result = x.hashCode();
          result = 31 * result + (y != null ? y.hashCode() : 0);
          return result;
      }
  }