Consider flow graph presented by the following edges

$-$N$=\{1,2,3,4,5,6,7\}$

$-$No$=\{0\}$

$-$N$+=(7\}$

$-$E$=\{((1,2),(1,7),(2,3),(2,4),(3,2),(4,5),(4,6),(5,6),(6,1)\}$

$-$defs and uses:

def $1=$

def $(2)=\{$y$\}$

use $(4)=\{$x$\}$;

use $(6)=($x$\}$;

use $(7)=($Y$\}$;

$1)$Give example of round$-$trip path

$2)$ Find the du pairs for variables x and y$.$

$3)$ Find the du paths for variables x and y$.$

$4)$Find test paths for "All Def Coverage" for variables x and y$.$

$5)$ Find test paths for "All Use Coverage" for variables x and y$.$

$6)$ Find test paths for "All DU Path Coverage" for variables x and y$.$