Treat `Documenter.indent` as a constant (#13960)

doc/development/tutorials/examples/autodoc_intenum.py

@@ -31,28 +31,27 @@ class IntEnumDocumenter(ClassDocumenter):
         except TypeError:
             return False
 
-    def add_directive_header(self) -> None:
-        super().add_directive_header()
-        self.add_line('   :final:', self.get_sourcename())
+    def add_directive_header(self, *, indent: str) -> None:
+        super().add_directive_header(indent=indent)
+        self.add_line('   :final:', self.get_sourcename(), indent=indent)
 
-    def add_content(
-        self,
-        more_content: StringList | None,
-    ) -> None:
-        super().add_content(more_content)
+    def add_content(self, more_content: StringList | None, *, indent: str) -> None:
+        super().add_content(more_content, indent=indent)
 
         source_name = self.get_sourcename()
         enum_object: IntEnum = self.props._obj
         use_hex = self.options.hex
-        self.add_line('', source_name)
+        self.add_line('', source_name, indent=indent)
 
         for the_member_name, enum_member in enum_object.__members__.items():  # type: ignore[attr-defined]
             the_member_value = enum_member.value
             if use_hex:
                 the_member_value = hex(the_member_value)
 
-            self.add_line(f'**{the_member_name}**: {the_member_value}', source_name)
-            self.add_line('', source_name)
+            self.add_line(
+                f'**{the_member_name}**: {the_member_value}', source_name, indent=indent
+            )
+            self.add_line('', source_name, indent=indent)
 
 
 def setup(app: Sphinx) -> ExtensionMetadata: