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

    public int fillWithOxygen ()
    {
        int steps = 0;

        return steps;
    }

    private Maze _theMaze;
}
@@ -97,24 +97,90 @@
 aze;%0A    %7D%0A%0A
+    // trace through the maze until we get back to the start%0A    %0A
     public i

Update OxygenFiller.java