public bool InitializeFromRawData( byte [] pData, DateTime lastModified) {
            byte[] compressedFile = null;
            using (MemoryStream mstocompress = new MemoryStream(pData)) {
                using (MemoryStream output = new MemoryStream()) {
                    using ( DeflateStream ds = new DeflateStream( output, CompressionMode.Compress ) ) {
                        mstocompress.CopyTo( ds );
                        compressedFile = new byte[output.Length];
                        output.Seek( 0, SeekOrigin.Begin );
                        output.Read( compressedFile, 0, compressedFile.Length );
                    }
                }
            }
    }