Read file from generic sources in chunks

public static IEnumerable<byte[]> ReadChunks(string source)
{
	using (Stream stream = IsUrl(source) ? WebRequest.Create(source).GetResponse().GetResponseStream() : new FileStream(source, FileMode.Open, FileAccess.Read, FileShare.Read))
	{
		const int sampleSize = 300;
		var fileSize = GetFileSize(source);
		if (fileSize > sampleSize)
			fileSize = sampleSize;
		var buffer = new byte[fileSize];
		if (stream == null)
			throw new Exception($"Não foi possível ler o arquivo {Path.GetFileName(source)}");
		int totalRead = 0;
		int bytesRead;
		while ((bytesRead = stream.Read(buffer, 0, buffer.Length)) > 0)
		{
			totalRead += bytesRead;
			yield return buffer;
		}
		Console.WriteLine($"[{(IsUrl(source) ? "URL" : "FILE")}]\t Quantidade pela Stream.Read: {totalRead}.");
	}
}