17 files declare their use of VariableObject in Business Rules 2.x

AddRoleToUser.php in src/Plugin/BusinessRulesAction/AddRoleToUser.php

BusinessRulesItemPluginBase.php in src/Plugin/BusinessRulesItemPluginBase.php

BusinessRulesProcessor.php in src/Util/BusinessRulesProcessor.php

CalculateValue.php in src/Plugin/BusinessRulesAction/CalculateValue.php

CustomValueVariable.php in src/Plugin/BusinessRulesVariable/CustomValueVariable.php

EntityEmptyVariable.php in src/Plugin/BusinessRulesVariable/EntityEmptyVariable.php

EntityFieldVariable.php in src/Plugin/BusinessRulesVariable/EntityFieldVariable.php

FetchEntityVariableAction.php in src/Plugin/BusinessRulesAction/FetchEntityVariableAction.php

FillEntityVariableFields.php in src/Plugin/BusinessRulesAction/FillEntityVariableFields.php

LoopThroughFieldVariable.php in src/Plugin/BusinessRulesAction/LoopThroughFieldVariable.php

LoopThroughViewResult.php in src/Plugin/BusinessRulesAction/LoopThroughViewResult.php

RemoveUserRole.php in src/Plugin/BusinessRulesAction/RemoveUserRole.php

SaveEntityVariableAction.php in src/Plugin/BusinessRulesAction/SaveEntityVariableAction.php

UrlVariable.php in src/Plugin/BusinessRulesVariable/UrlVariable.php

UserVariable.php in src/Plugin/BusinessRulesVariable/UserVariable.php

UserVariableHasRole.php in src/Plugin/BusinessRulesCondition/UserVariableHasRole.php

ViewResultVariable.php in src/Plugin/BusinessRulesVariable/ViewResultVariable.php