The project is a mandatory assignment of INF1010 course at the UiO at spring 2016 (http://heim.ifi.uio.no/inf1010/2016/oblig/11/oppgave.pdf).
To start a GUI interface SudokuGUI should've been driven. The FileChooser is the first state of GUI where user is obliged to choose a file with sudoku board from the folder brett/.