Creation of dynamic property time

I have updated this issue in attached patch1

Committed, thanks for the patch.
I'm went with #3, which has a better comment.

{@inheritdoc} is not appropriate here: the parent does not define this property, there is nothing to inherit.

Also, a point of issue queue etiquette @Mohd Sahzad:
Give someone more than a minute to post a patch when they open a new issue before you assign it to yourself. If someone else has already posted a patch, there's no good reason to post a 2nd patch which does the same thing. If you do post a followup patch, make sure you're specifying the reasons for doing so in your comment.

Is there anything still needed on this or can it be closed?

should have been marked "fixed"

while i have your attention though, i'll cross-post a big MR in #3398897: Creation of dynamic property $key which attempts to address the many many other dynamic properties.