Closes gh-15569

Closes gh-15455

* pr/15583:
  Polish "Add unit test for cassandra health checker"
  Add unit test for cassandra health checker

Closes gh-15583

See gh-15583

* pr/15585:
  Replace Collections sort with list sort() method

Closes gh-15585

* pr/15582:
  Use hasFieldOrPropertyWithValue where possible

Closes gh-15582

* pr/15575:
  Polish "Use Optional value in more functional style"
  Use Optional value in more functional style

Closes gh-15575

See gh-15575

* pr/15394:
  Polish "Avoid NPE when replacement property does not exist"
  Avoid NPE when replacement property does not exist

Closes gh-15394

See gh-15394

* pr/15563:
  Polish "Simplify code by using for-each loop"
  Simplify code by using for-each loop

Closes gh-15563

See gh-15563

Closes gh-15564

* pr/15562:
  Fix system properties override example

Closes gh-15562

* pr/15559:
  Polish "Replace indexOf() with a call to the contains()"
  Replace indexOf() with a call to the contains()

Closes gh-15559

See gh-15559

* pr/15554:
  Polish "Replace redundant call to class isInstance() with instanceof"
  Replace redundant call to class isInstance() with instanceof

Closes gh-15554

See gh-15554

Closes gh-15488

* gh-15550:
  Polish "Stop JtaAutoConfiguration from enabling JtaProperties when not used"
  Stop JtaAutoConfiguration from enabling JtaProperties when not used

Closes gh-15550

See gh-15550