func (ww write) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "text/plain")
	w.Header().Set("Content-Length", fmt.Sprintf("%d", len(ww)))
	fmt.Fprintf(w, string(ww))
}
ServeHTTP writes the string to the http.ResponseWriter, sets the Content-Length and
the Content-Type to text/plain
package helper
import (
	"fmt"
	"net/http"
	"net/http/httptest"
	"strings"
)
type write string