func Outf(format string, v ...interface{}) {
	defaultMLog.Outf(format, v...)
}
Outf write to all registered output writers.
The default registered output writer is os.Stdout.
package mlog
import (
	"io"
	"os"
)
const (
	defTimeFormat = "2006-01-02 15:04:05 MST"
)
var defaultMLog = NewMultiLogger(defTimeFormat, "",
	[]NamedWriter{
		NewNamedWriter("stdout", os.Stdout),
	},
	[]NamedWriter{
		NewNamedWriter("stderr", os.Stderr),
	})
func Errf(format string, v ...interface{}) {
	defaultMLog.Errf(format, v...)
}
func Fatalf(format string, v ...interface{}) {
	defaultMLog.Fatalf(format, v...)
}
func Flush() {
	defaultMLog.Flush()
}