func (s *Scratch) HistogramFinished(maxSymbol uint8, maxCount int) {
	s.maxCount = maxCount
	s.symbolLen = uint16(maxSymbol) + 1
	s.clearCount = maxCount != 0
}
HistogramFinished can be called to indicate that the histogram has been populated.
maxSymbol is the index of the highest set symbol of the next data segment.
maxCount is the number of entries in the most populated entry.
These are accepted at face value.
package fse
import (
	"errors"
	"fmt"
	"math/bits"
)
const (
	maxMemoryUsage     = 14
	defaultMemoryUsage = 13
	maxTableLog     = maxMemoryUsage - 2
	maxTablesize    = 1 << maxTableLog
	defaultTablelog = defaultMemoryUsage - 2
	minTablelog     = 5
	maxSymbolValue  = 255
)
var (
	ErrIncompressible = errors.New("input is not compressible")
	ErrUseRLE = errors.New("input is single value repeated")
)
type Scratch struct {
	count          [maxSymbolValue + 1]uint32
	norm           [maxSymbolValue + 1]int16
	symbolLen      uint16  
	actualTableLog uint8   
	br             byteReader
	bits           bitReader
	bw             bitWriter
	ct             cTable       
	decTable       []decSymbol  
	zeroBits       bool         
	clearCount     bool         
	maxCount       int          
	Out []byte
	MaxSymbolValue uint8
	TableLog uint8
	DecompressLimit int
}
func (s *Scratch) Histogram() []uint32 {
	return s.count[:]
}