Also:
- change 2 variable/property names, both internal.
- format empty function.
Towards getting it fully phpcs compliant. Note this does not
fix the missing (in all methods) phpdoc blocks.
There are various places where it's not guaranteed that the
variable being used is array, and instead, can be null, bool, int...
We need to check that because php74 warns about it.
Where possible we have used the coalesce operator as
replacement for isset() ternary operations.
Eloy Lafuente (stronk7)