remove isset() and replaced with array_key_exists()

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (d99759b) 100.00% compared to head (c5a7f1d) 100.00%. Report is 13 commits behind head on develop.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## develop #184 +/- ## =========================================== Coverage 100.00% 100.00% Complexity 221 221 =========================================== Files 22 22 Lines 675 675 =========================================== Hits 675 675 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.