Oracle PL/SQL/Object Oriented Database/NOT INSTANTIABLE

instantiate shape error

 
SQL>
SQL> create or replace
  2  type shape as object(number_of_sides number, not instantiable member function calculate_area return number
  3    )
  4  not instantiable not final
  5  /
Type created.
SQL>
SQL>
SQL>
SQL> declare
  2   l_shape shape;
  3  begin
  4   l_shape := shape( 2 );
  5  end;
  6  /
 l_shape := shape( 2 );
            *
ERROR at line 4:
ORA-06550: line 4, column 13:
PLS-00713: attempting to instantiate a type that is NOT INSTANTIABLE
ORA-06550: line 4, column 2:
PL/SQL: Statement ignored

SQL>
SQL>