CREATE MULTISET TABLE with NON UNIQUE PRIMARY INDEX in Teradata

Non unique primary index is generally specified for MULTISET tables.
The purpose of MULTISET tables is to allow users to enter duplicate records.
The presence the UNIQUE PRIMARY INDEX in a MULTISET table DDL is absolutely valid however it destroys the actual usage of MULTISET tables.

CREATE MULTISET TABLE tbl_employee
(
name VARCHAR(20),
id INT,
roll_no INT
)
PRIMARY INDEX (id, roll_no)