//f represnts io.file

// incase I don't need lumberjack and want to
// write to both Stdout and file
multi := io.MultiWriter(os.Stdout, f)
l := ConfigureLogrus(multi)


// in case I don't need lumberjack and want to
// write to file only
l := ConfigureLogrus(f)


// incase I don't need lumberjack and want to
// write to stdout only
l := ConfigureLogrus(os.Stdout)

//in case I want lumberjack and stdout
//lets say l is logrus instance
multi := io.MultiWriter(os.Stdout, l)
j := ConfigureLogrus(l)

and so on.