Pick a Java method from Simple$2.$java $($My Course Content$->$Week $12-13)$ and write a single JUnit test for it$.$ Unit test should only test one functionality such as specific path in that method or parameter or value in that method. public double average$()$

$\{$

int sumNums $=$ sum$()$;

return $($average$/3\mathrm{.}0)$;

$\}$