NOT NULL constraints are not visible for object tables (4375908)

NOT NULL constraints are not visible for object tables

NOT NULL constraints excluded from object table scripts.
Steps to reproduce the issue:

Run the script below:
CREATE TYPE test_object_t AS OBJECT
(
id NUMBER,
hiredate DATE,
desc_t VARCHAR2 (255),
MEMBER FUNCTION f_test
RETURN VARCHAR2
) NOT FINAL
/

CREATE OR REPLACE TYPE BODY test_object_t
IS
MEMBER FUNCTION f_test
RETURN VARCHAR2
AS
BEGIN
RETURN 'V1.0.0';
END;
END;
/

CREATE TABLE test_objects OF test_object_t
NOT SUBSTITUTABLE AT ALL LEVELS
(
CONSTRAINT test_objects_pk PRIMARY KEY (id)
)
OBJECT ID PRIMARY KEY
/

ALTER TABLE test_objects
MODIFY (hiredate CONSTRAINT hiredate_nn NOT NULL)
/

ALTER TABLE test_objects
MODIFY (desc_t CONSTRAINT desc_nn NOT NULL)
/

If you run describe test_objects; you see

TABLE test_objects
 Name                                      Null?    Type                        
 ----------------------------------------- -------- ----------------------------
 ID                                            NOT NULL NUMBER                      
 HIREDATE                              NOT NULL DATE                        
 DESC_T                                  NOT NULL VARCHAR2(255)     

notice the not nulls created before with the alter statements for HIREDATE and DESC_T.

The not nulls can be seen in the constrains and column tabs in schema browser.
The problem is that Toad does not show this information(not null) in any script anywhere (f4 , schema browser, schema compare or extract dll.)