Name is the name registered for the gzip compressor.
const Name = "gzip"
func SetLevel(level int) error
SetLevel updates the registered gzip compressor to use the compression level specified (gzip.HuffmanOnly is not supported). NOTE: this function must only be called during initialization time (i.e. in an init() function), and is not thread-safe.
The error returned will be nil if the specified level is valid.