import java.util.*;public class Bureau {   // Agency code plus bureau code uniquely identify a bureau    // Bureau code alone is definitely not sufficient  private String code;  private String name;  private String year;  private String agencyCode;    private List   accounts = new ArrayList();    private static Map instances = new HashMap();  // Use a private constructor so instantiators   // have to use the factory method  private Bureau(String name, String code, String agencyCode,     String year) {            this.name = name;    this.code = code;    this.agencyCode = agencyCode;    this.year = year;      }    public static Bureau getInstance(String name, String code,    String agencyCode, String year) {            String key = agencyCode+" "+code+" "+year;    Bureau bureau = (Bureau) instances.get(key);    if (bureau == null) {      bureau = new Bureau(name, code, agencyCode, year);      instances.put(key, bureau);    }        return bureau;          }    public void add(Account account) {    if (!accounts.contains(account)) accounts.add(account);       }    public String getXML() {            StringBuffer result = new StringBuffer("    <Bureau>\r\n");    result.append("      <Name>" + name + "</Name>\r\n");    result.append("      <Code>" + code + "</Code>\r\n");    Iterator iterator = accounts.iterator();    while (iterator.hasNext()) {      Account account = (Account) iterator.next();      result.append(account.getXML());    }    result.append("    </Bureau>\r\n");    return result.toString();      }          }