Perserve class in Catalog.clone

Author: duckontheweb

pystac/catalog.py

@@ -471,7 +471,8 @@ def to_dict(self, include_self_link: bool = True) -> Dict[str, Any]:
         return d
 
     def clone(self) -> "Catalog":
-        clone = Catalog(
+        cls = self.__class__
+        clone = cls(
             id=self.id,
             description=self.description,
             title=self.title,

tests/test_catalog.py

@@ -1153,3 +1153,9 @@ def test_from_file_returns_subclass(self) -> None:
         custom_catalog = self.BasicCustomCatalog.from_file(self.TEST_CASE_1)
 
         self.assertIsInstance(custom_catalog, self.BasicCustomCatalog)
+
+    def test_clone(self) -> None:
+        custom_catalog = self.BasicCustomCatalog.from_file(self.TEST_CASE_1)
+        cloned_catalog = custom_catalog.clone()
+
+        self.assertIsInstance(cloned_catalog, self.BasicCustomCatalog)