/// <summary>
/// Create a <c>GZipStream</c> using the specified <c>CompressionMode</c> and the
/// specified <c>CompressionLevel</c>, and explicitly specify whether the
/// stream should be left open after Deflation or Inflation.
/// </summary>
///
/// <remarks>
///
/// <para>
/// This constructor allows the application to request that the captive stream
/// remain open after the deflation or inflation occurs. By default, after
/// <c>Close()</c> is called on the stream, the captive stream is also
/// closed. In some cases this is not desired, for example if the stream is a
/// memory stream that will be re-read after compressed data has been written
/// to it. Specify true for the <paramref name="leaveOpen"/> parameter to
/// leave the stream open.
/// </para>
///
/// <para>
/// As noted in the class documentation, the <c>CompressionMode</c> (Compress
/// or Decompress) also establishes the "direction" of the stream. A
/// <c>GZipStream</c> with <c>CompressionMode.Compress</c> works only through
/// <c>Write()</c>. A <c>GZipStream</c> with <c>CompressionMode.Decompress</c> works only
/// through <c>Read()</c>.
/// </para>
///
/// </remarks>
///
/// <example>
/// This example shows how to use a <c>GZipStream</c> to compress data.
/// <code>
/// using (System.IO.Stream input = System.IO.File.OpenRead(fileToCompress))
/// {
/// using (var raw = System.IO.File.Create(outputFile))
/// {
/// using (Stream compressor = new GZipStream(raw, CompressionMode.Compress, CompressionLevel.BestCompression, true))
/// {
/// byte[] buffer = new byte[WORKING_BUFFER_SIZE];
/// int n;
/// while ((n= input.Read(buffer, 0, buffer.Length)) != 0)
/// {
/// compressor.Write(buffer, 0, n);
/// }
/// }
/// }
/// }
/// </code>
/// <code lang="VB">
/// Dim outputFile As String = (fileToCompress & ".compressed")
/// Using input As Stream = File.OpenRead(fileToCompress)
/// Using raw As FileStream = File.Create(outputFile)
/// Using compressor As Stream = New GZipStream(raw, CompressionMode.Compress, CompressionLevel.BestCompression, True)
/// Dim buffer As Byte() = New Byte(4096) {}
/// Dim n As Integer = -1
/// Do While (n <> 0)
/// If (n > 0) Then
/// compressor.Write(buffer, 0, n)
/// End If
/// n = input.Read(buffer, 0, buffer.Length)
/// Loop
/// End Using
/// End Using
/// End Using
/// </code>
/// </example>
/// <param name="stream">The stream which will be read or written.</param>
/// <param name="mode">Indicates whether the GZipStream will compress or decompress.</param>
/// <param name="leaveOpen">true if the application would like the stream to remain open after inflation/deflation.</param>
/// <param name="level">A tuning knob to trade speed for effectiveness.</param>
public GZipStream(Stream stream, CompressionMode mode, CompressionLevel level, bool leaveOpen)
{
_baseStream = new ZlibBaseStream(stream, mode, level, ZlibStreamFlavor.GZIP, leaveOpen);
}