@SuppressWarnings("unchecked")
 public boolean equals(Object o) {
   if (o instanceof Set) {
     Set that = (Set) o;
     if (this.size != that.size()) return false;
     int pos = 0;
     while (pos < capa) {
       Object k = _getKey(pos);
       if (k == NULL || k == DEL) {
         pos++;
         continue;
       }
       if (!that.has(k)) return false;
       pos++;
     }
     return true;
   }
   return false;
 }