func NewWriterLevel(dst io.Writer, level int) *Writer {
	return NewWriterOptions(dst, WriterOptions{
		Quality: level,
	})
}
NewWriterLevel is like NewWriter but specifies the compression level instead
of assuming DefaultCompression.
The compression level can be DefaultCompression or any integer value between
BestSpeed and BestCompression inclusive.
package brotli
import (
	"errors"
	"io"
)
const (
	BestSpeed          = 0
	BestCompression    = 11
	DefaultCompression = 6
)
type WriterOptions struct {
	Quality int
	LGWin int
}
var (
	errEncode       = errors.New("brotli: encode error")
	errWriterClosed = errors.New("brotli: Writer is closed")
)
func NewWriter(dst io.Writer) *Writer {
	return NewWriterLevel(dst, DefaultCompression)
}