custom field Views plugin, test not using createEntity

[jackrabbithanna]

Overview

I saw a request for some performance optimization of Views with a large dataset
https://civicrm.stackexchange.com/questions/48376/drupal-views-using-civicrm-entity-with-relationships-added-takes-too-long-to-ren

Was provided an XHProf profile, and we discovered an inordinate amount of time spent cloning entities.

Optimize CustomEntityField plugin.

We know that cloning the entity takes ALOT of time.
I also wonder if we can get rid of the API call to CustomValue

Before

Molasses is faster

After

Competitive speed vs. Molasses.

[jackrabbithanna]

Test passes commenting out createEntity() are not a sign all is well.
For sure YesNo field type needs help. If add a custom field of that type to the View, then if there is no value, still "No" is rendered.
Same for the datetime conversion done in that plugin.

There maybe other reasons why that method / entity processing needs be done.