PlayerTestScene
SetUpSteps
HasCustomSteps
Ruleset
"Member is explicitly initialized to its default value"
There are test scenes using current value of ruleset bindable on their BDL (example in TestSceneSliderSnaking's BDL)
Should be recognized as a normal protected method in its declaring class.
Also makes `CreatePlayerRuleset()` and `CreateRulesetForSkinProvider()` not-null to avoid unwanted behaviour with their derivers
CreateRuleset