tests for setting statics which are not defined on the object as built-in PHP statics
testHasAndAddExtension : At the moment, this does NOT remove the extension due to parameterized naming, meaning the extension will remain added in further test cases. See
Description
testHasAndAddExtension
: At the moment, this does NOT remove the extension due to parameterized naming, meaning the extension will remain added in further test cases. SeeSee: https://github.com/silverstripe/silverstripe-framework/blob/cf78a9d785b9959a92dfb52c2a456bea80a4c567/tests/php/Core/ObjectTest.php#L26-L28