// HERE WE SHOULD CHECK THE LENGTH OF callback

@co_call(par_area,par_class,"getSchema",par_area=>par_area,par_class=>par_class,par_id=>par_id,callback=>'coa_GetElement(cnx,callbacks,0)', representant_level=>-1);

@co_call(par_area,par_class,"getRelatedClasses",par_area=>par_area,par_class=>par_class,par_id=>par_id,callback=>'coa_GetElement(cnx,callbacks,1)');
@co_call(par_area,par_class,"get",par_area=>par_area,par_class=>par_class,par_id=>par_id,callback=>'coa_GetElement(cnx,callbacks,2)');