I found `Option[Map[String, String]]` works weirdly like this:

```
 scala> val fileInfo: Option[Map[String, String]] = Some(Map( "type" -> "hoge" ))
 fileInfo: Option[Map[String,String]] = Some(Map(type -> hoge))

 scala> fileInfo.get("type")
 res1: String = hoge

```

I think the `Option` "get" method doesn't take any argument, so this is super weird for me. Why does it work? Is it an implicit conversion or a bug? I want to make sure how it works.

My specifications are:

* Scala version 2.9.2
* Java 1.6.0\_43