https://microsoft.github.io/cpprestsdk/classpplx_1_1___continuation__func__transformer_3_01void_00_01___out_type_01_4.html
C++ Rest SDK: pplx::_Continuation_func_transformer void, _OutType Class Template Reference
https://microsoft.github.io/cpprestsdk/classpplx_1_1___continuation__func__transformer.html
C++ Rest SDK: pplx::_Continuation_func_transformer _InpType, _OutType Class Template Reference