func Format(f string) Option {
	return func(l *Logger) {
		l.format = f
	}
}
Format sets output layout, overwrites all options for individual parts, i.e. Caller*, Msec and LevelBraces
package lgr
import "io"
type Option func(l *Logger)
func Out(w io.Writer) Option {
	return func(l *Logger) {
		l.stdout = w
	}
}
func Err(w io.Writer) Option {
	return func(l *Logger) {
		l.stderr = w
	}
}
func Debug(l *Logger) {
	l.dbg = true
}
func Trace(l *Logger) {
	l.dbg = true
	l.trace = true
}
func CallerDepth(n int) Option {
	return func(l *Logger) {
		l.callerDepth = n
	}
}