WANG CHAO

This issue can be closed, as `isFileExists` is now edited to be: ``` public static boolean isFileExists(Path file) { return Files.exists(file) && Files.isRegularFile(file); } ```

> I wonder if this can be automated, using TestFx for example. [Snapshot API](https://docs.oracle.com/javase/8/javafx/api/javafx/scene/Node.html#snapshot-javafx.util.Callback-javafx.scene.SnapshotParameters-javafx.scene.image.WritableImage-) of JavaFx can be considered.

If I remember correctly, coverall is deprecated because the Gradle plugin we are using is not being updated anymore, and using CodeCov, there is no need for a plugin there.