what should i do for the last todo's here : $\}$

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$//$ TODO:: let detached threads know they need to shut down using the flag you

$//$ created in the thread structure. You may only set the flag once here $($you should

$//$ not have more than one flag$)$ and it must be in a thread safe manner.

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$//$ TODO:: Wait for all detached threads to finish without using a busy$-$wait loop.

$//$ You must wait for the number of threads to change before checking again to avoid

$//$ wasting CPU cycles.

$//($HINT: Remember there is a specific object that can Wait for a Condition$)$

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