Another question on class constructor

["Rego, P." <pvrego@gmail.com>]

I have a class defined as:

   type Test_Class is tagged limited
      record
         Info    : Integer;
         Value   : Float;
         Primary : Primary_Task (Test_Class'Access);
      end record;

I need build a one-step constructor for my class in the form

   function Construct (T : access Test_Class) return Test_Class_Ptr is
   begin
      return new Test_Class'(Info => T.Info + 1,
                             Value => 0.0,
                             Primary => [WHAT I WANNA KNOW]);
   end Construct;

Currently my code is:

-- test_pkg.ads
package Test_Pkg is
   type Test_Class;
   type Test_Class_Ptr is access all Test_Class;

   task type Primary_Task (This_Test : access Test_Class) is
      pragma Storage_Size (1000);
   end Primary_Task;

   type Test_Class is tagged limited
      record
         Info    : Integer;
         Value   : Float;
         Primary : Primary_Task (Test_Class'Access);
      end record;

   function Construct (T : access Test_Class) return Test_Class_Ptr;
end Test_Pkg;

-- test_pkg.adb
with Text_IO; use Text_IO;
package body Test_Pkg is
   [...]

   function Construct (T : access Test_Class) return Test_Class_Ptr is
      T_Ptr : constant Test_Class_Ptr := new Test_Class;
   begin
      T_Ptr.Info := T.Info + 1;
      T_Ptr.Value := 0.0;
      return T_Ptr;
   end Construct;
end Test_Pkg;

So, how can I code it? What should I put in Primary => [...] code? Should I change the definition of Primary : Primary_Task (Test_Class'Access); in Test_Class definition? Thanks.