public static ArrayBuilder <T> GetInstance(int capacity)
        {
            ArrayBuilder <T> builder = GetInstance();

            builder.EnsureCapacity(capacity);
            return(builder);
        }
        public static ArrayBuilder <T> GetInstance(int capacity, T fillWithValue)
        {
            ArrayBuilder <T> builder = GetInstance();

            builder.EnsureCapacity(capacity);

            for (int i = 0; i < capacity; i++)
            {
                builder.Add(fillWithValue);
            }

            return(builder);
        }