public class OxygenFiller
{
    public OxygenFiller (Maze theMaze)
    {
        _theMaze = theMaze;
    }

    private Maze _theMaze;
}
@@ -101,16 +101,108 @@
 %0A    %7D%0A%0A
+    public int fillWithOxygen ()%0A    %7B%0A        int steps = 0;%0A%0A        return steps;%0A    %7D%0A%0A
     priv

Update OxygenFiller.java