implementation like on diagram-2 concode_field_sep AsyncVkClient apacheVkClient concode_elem_sep PersonService service concode_elem_sep AsyncVkClient dummyVkClient concode_field_sep List<ApiPerson> getAllAsync concode_elem_sep List<ApiPerson> getAsyncPersons1
List < ApiPerson > function ( ) { return getAllAsync ( apacheVkClient ) ; }