+fun extern_kind: MClassKind do return once new MClassKind("extern class", false, true, false)
+# The class kind `subset`
+fun subset_kind: MClassKind do return once new MClassKind("subset", true, false, false)
+
+# A standalone pre-constructed model used to test various model-related methods.
+#
+# When instantiated, a standalone model is already filled with entities that are exposed as attributes.
+class ModelStandalone
+ super Model
+
+ redef var location = new Location.opaque_file("ModelStandalone")
+
+ # The first module
+ var mmodule0 = new MModule(self, null, "module0", location)
+
+ # The root Object class
+ var mclass_o = new MClass(mmodule0, "Object", location, null, interface_kind, public_visibility)
+
+ # The introduction of `mclass_o`
+ var mclassdef_o = new MClassDef(mmodule0, mclass_o.mclass_type, location)
+end
+
+# A standalone model with the common class diamond-hierarchy ABCD
+class ModelDiamond
+ super ModelStandalone
+
+ # A, a simple subclass of Object
+ var mclass_a = new MClass(mmodule0, "A", location, null, concrete_kind, public_visibility)
+
+ # The introduction of `mclass_a`
+ var mclassdef_a: MClassDef do
+ var res = new MClassDef(mmodule0, mclass_a.mclass_type, location)
+ res.set_supertypes([mclass_o.mclass_type])
+ res.add_in_hierarchy
+ return res
+ end
+
+ # B, a subclass of A (`mclass_a`)
+ var mclass_b = new MClass(mmodule0, "B", location, null, concrete_kind, public_visibility)
+
+ # The introduction of `mclass_b`
+ var mclassdef_b: MClassDef do
+ var res = new MClassDef(mmodule0, mclass_b.mclass_type, location)
+ res.set_supertypes([mclass_a.mclass_type])
+ res.add_in_hierarchy
+ return res
+ end
+
+ # C, another subclass of A (`mclass_a`)
+ var mclass_c = new MClass(mmodule0, "C", location, null, concrete_kind, public_visibility)
+
+ # The introduction of `mclass_c`
+ var mclassdef_c: MClassDef do
+ var res = new MClassDef(mmodule0, mclass_c.mclass_type, location)
+ res.set_supertypes([mclass_a.mclass_type])
+ res.add_in_hierarchy
+ return res
+ end
+
+ # D, a multiple subclass of B (`mclass_b`) and C (`mclass_c`)
+ var mclass_d = new MClass(mmodule0, "D", location, null, concrete_kind, public_visibility)
+
+ # The introduction of `mclass_d`
+ var mclassdef_d: MClassDef do
+ var res = new MClassDef(mmodule0, mclass_d.mclass_type, location)
+ res.set_supertypes([mclass_b.mclass_type, mclass_c.mclass_type])
+ res.add_in_hierarchy
+ return res
+ end
+end