How to get a report of a whole directory when using it as Go module 

I am using the module as following

```go
import 	"github.com/urfave/cli/v2"
//.. 
  enry.GetLanguageByContent(file, b)
```
But what's the receiver( function) responsible for get the breakdown of the whole directory.

Should i copy/paste your main.go to my application ?!
