func NewChanWriter() (ChanWriter, chan string) {
	output := make(chan string, 128)
	return ChanWriter{output: output}, output
}
NewChanWriter returns a new ChanWriter and the output channel.
package testutils
import (
	"bytes"
	"encoding/json"
	"errors"
	"fmt"
	"math/rand"
	"net/http"
	"time"
	"github.com/renproject/darknode/jsonrpc"
	"github.com/renproject/darknode/tx/txutil"
	"github.com/renproject/id"
	"github.com/renproject/pack"
)
type ChanWriter struct {
	output chan string
}