[Lazarus] If Assigned ()

[ajv]

Hello,

How can I test if a "Procedure Of Object" is assigned?

example: (mode delphi under Linux)
Var PO : Procedure Of Object;
PO := Nil;   // OK
If Assigned (PO) Then Writeln ('This should not be printed');     // It 
is printed !!

In Delphi  : Function Assigned (Const P) : Boolean
In Lazarus : Function Assigned (P : Pointer) : Boolean;

Is this a bug?
Should I write a overloaded function?

Thanks