func NewComposer(w io.Writer) *Composer {
	return &Composer{w: w}
}
Create a new Composer with the given
io.Writer and returns back it's address
package cbor
import (
	"encoding/binary"
	"fmt"
	"io"
	"math"
	"math/big"
	"time"
	"unsafe"
)
type Composer struct {
	header     byte
	w          io.Writer
	indefinite bool
}