Singular vs plural after “One example of such”

grammatical-numbergrammaticality

In sentences like "One example of such X is Y" should X be singular, plural or can it be either?

For example:

Some methods are {description of this group of methods}.
One example of such methods is the {name of some specific method}.

Is this grammatically correct? Or should it be "one example of such a method" since we are talking about a singular example?

Another example:

These utilities form a significant portion of {…}.
One example of such a utility is a water cooling system.

I think, I've seen both singular and plural versions in fairly respectable sources, but now I'm having doubts if both are valid.

Here is a very similar question, but I'm not sure if similar reasoning applies here.

Both are often grammatical. The logical form (bolding mine):

One example of such differences in regulatory treatment is the Standardised Approach in the CRR, which applies lower risk weights to certain ...

(Compare 'Such differences in regulatory treatment are known to exist; one example is the Standardised Approach in the CRR'.)

Many such examples are to be found in a Google search for "one example of such" -"one example of such a"

...............

But the 'distributive singular' may also be used:

Mass phishing campaigns are one example of such an attack.

[O]ne example of such a risk would be dangerous electrical installations or wiring.

Again, many such examples are to be found in Google searches for "one example of such a" / "one example of such an".