public UserPrincipal(String name) 
{
        if (name == null) throw new IllegalArgumentException("name cannot be null");
        this.name = name;
}

 public boolean equals(Object o) 
{
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        final UserPrincipal that = (UserPrincipal) o;
        if (!name.equals(that.name)) return false;
        return true;
}

 public String getName() 
{
        return name;
}

 public int hashCode() 
{
        if (hash == 0) {
            hash = name.hashCode();
        }
        return hash;
}

 public String toString() 
{
        return name;
}