Is "Signifying nothing" an example of litotes?

In Macbeth's Tomorrow speech

To-morrow, and to-morrow, and to-morrow,
Creeps in this petty pace from day to day,
To the last syllable of recorded time;
And all our yesterdays have lighted fools
The way to dusty death.
Out, out, brief candle!
Life's but a walking shadow, a poor player
That struts and frets his hour upon the stage
And then is heard no more.
It is a tale
Told by an idiot, full of sound and fury Signifying nothing."
— Macbeth (Act 5, Scene 5, lines 17-28)

is the last line Signifying nothing litotes?

I have to analyze this segment for school, and I'm a little unclear of what litotes is in practice.

As a figure of speech litotes means understatement for ironic emphasis, often by denying the opposite.

Examples form Shakespeare include "not without cause" [Julius Caesar] or "we have seen better days" [As You Like It]. I would not say "signifying nothing" was an example, as Macbeth means precisely what he says about the futility of human existence.

No. Litotes is "a form of understatement, always deliberate and with the intention of emphasis." An example of litotes could be "not bad" (which means "good"), or "you are not wrong" (meaning "you are right"). It is principally defined by a double negative.

Signifying nothing does not include a denial of the opposite, and neither is it an understatement. It is therefore not an example of litotes.