/** 
 * Holds a pair of strings, which can be tested for equality
 * @author Scot Drysdale
 */
public class StringPair {
  private String s1, s2;  // The pair of strings
  
  /**
   * Contruct a new pair
   * @param str1 the first string
   * @param str2 the second string
   */
  public StringPair(String str1, String str2) {
    s1 = str1;
    s2 = str2;
  }
  
  public boolean equals(Object other) {
  	  if(!(other instanceof StringPair))
  	  	  return false;
    StringPair otherPair = (StringPair) other;
    
    return s1.equals(otherPair.s1) && s2.equals(otherPair.s2);
  }
  
  public int hashCode() {
    return s1.hashCode() + 31*s2.hashCode();
  }
}