public bool copy(
            string s /* storage account */,
            string c1 /* source container name */,
            string b1 /* source blob name */,
            string c2 /* dest container name */,
            string b2 /* dest blob name */)
        {
            if (string.IsNullOrEmpty(s)) s = "default";

            BlobHelper bh = new BlobHelper(s);

            if (string.IsNullOrEmpty(c2))
            {
                c2 = c1;
            }

            if (string.IsNullOrEmpty(b2))
            {
                b2 = b1;
            }

            if (!string.IsNullOrEmpty(c1))
            {
                if (!string.IsNullOrEmpty(b1))
                {
                    return bh.CopyBlob(c1, b1, c2, b2);
                }
                else
                {
                    return bh.CopyContainer(c1, c2);
                }
            }

            return false;
        }