+SimpleOptCheckType = Union[KconfigCheck, CmdlineCheck, SysctlCheck, VersionCheck]
+SimpleOptCheckTypes = (KconfigCheck, CmdlineCheck, SysctlCheck, VersionCheck)
+SimpleNamedOptCheckType = Union[KconfigCheck, CmdlineCheck, SysctlCheck]
+SimpleNamedOptCheckTypes = (KconfigCheck, CmdlineCheck, SysctlCheck)
+
+# 2) complex objects that may contain complex and simple objects
+ComplexOptCheckType = Union[OR, AND]
+ComplexOptCheckTypes = (OR, AND)
+
+# 3) objects that can be added to the checklist
+ChecklistObjType = Union[KconfigCheck, CmdlineCheck, SysctlCheck, OR, AND]
+
+# 4) all existing objects
+AnyOptCheckType = Union[KconfigCheck, CmdlineCheck, SysctlCheck, VersionCheck, OR, AND]