Support for obtaining the file extension of a file path's name is added via a new default method `java.nio.file.Path::getExtension`. Some examples:

| File Name String | Extension |
|------------------|-----------|
| "foo.tar.gz" | "gz" |
| "foo.bar" | "bar" |
| "foo." | "" |
| "foo" | `null` |
| ".bar" | `null` |