func Fatalf(format string, a ...interface{}) {
	log.Fatalf(format+"\n", a...)
}
Fatalf outputs a fatal log line with a formatting string.
package logging
import (
	"fmt"
	"log"
	"os"
)
func Errorf(format string, a ...interface{}) (int, error) {
	return fmt.Fprintf(os.Stderr, format+"\n", a...)
}
func Error(a ...interface{}) (int, error) {
	return fmt.Fprintln(os.Stderr, a...)
}
func Infof(format string, a ...interface{}) (int, error) {
	return fmt.Printf(format+"\n", a...)
}
func Info(a ...interface{}) (int, error) {
	return fmt.Println(a...)
}