The compression level to use.
This property is only applicable when using the LZMA CompressionMethod. This property specifies the level of compression to be used,valid values are: 1, 2, 3, 4 and 5. Higher values will cause the class to compress better; lower values will cause the class to compress faster. The default value is 3.
You may optionally set this property from within the BeginFile event to apply different levels of compression to different files.