code: public static BitStore store(int size) {
  		if (size < 0) throw new IllegalArgumentException();
  		switch (size) {
  		case 0 : return VoidBitStore.MUTABLE;
  		case 1 : return new Bit();
  		case 64: return new LongBitStore();
  		default:
  			return size < 64 ?
  					new LongBitStore().range(0, size) : // assumed preferred irrespective of storage preference
  					                                    // because allocation of array is avoided
  					preferredType.sized(size);
  		}
  	}
docs: Creates a new mutable {@link BitStore} instance with the specified size.
  The implementing class is likely to vary with the requested size.
  
  @param size
  the capacity, in bits, of the new {@link BitStore}
  
  @return a new mutable {@link BitStore} of the specified size.