code: @Override
  	public int compareNumericallyTo(BitStore that) {
  		if (that instanceof BitVector) {
  			if (this == that) return 0; // cheap check
  			BitVector v = (BitVector) that;
  			return this.size() < that.size() ? compareNumeric(this, v) : -compareNumeric(v, this);
  		}
  		return BitStore.super.compareNumericallyTo(that);
  	}
docs: comparable methods