$8\mathrm{.}1.$ Testing breadth$-$first search in a labyrinth

Modify your breadth$-$first solver to print the trace as below. Test $1$: the labyrinth in Fig. $8\mathrm{.}1.$ Test $2$: the $179$ labyrinth and start at $x=9,Y=6$ as shown in Fig. $7\mathrm{.}5.$ Test $3$: build your $20\mathrm{.}15$ labyrinth with multiple islands, the resulting path length over $100$ productions and multiple deadends.