code: func WriteFloat32(space []byte, val float32) []byte {
  	abs := math.Abs(float64(val))
  	fmt := byte('f')
  	// Note: Must use float32 comparisons for underlying float32 value to get precise cutoffs right.
  	if abs != 0 {
  		if float32(abs) < 1e-6 || float32(abs) >= 1e21 {
  			fmt = 'e'
  		}
  	}
  	return append(space, strconv.FormatFloat(float64(val), fmt, -1, 32)...)
  }
docs: // WriteFloat32 write float32 to stream