strict
Boxes given GLazy into GStrictLazy which throws an error on delegate access if no value is present
Receiver
GLazy to box
Return
GStrictLazy assuming non-nullable values
Boxes given GMutableLazy into GStrictMutableLazy which throws an error on delegate access if no value is present and prevents setting null values on delegate assignments.
Receiver
GMutableLazy to box
Return
GStrictMutableLazy assuming non-nullable values