anchor.diff:      get_provider_eff_users/0,
   
       get_cert_chain_ders/0,
  -    gs_protocol_supported_versions/0
  +    gs_protocol_supported_versions/0,
  +
  +    perform_io_test/2
   ]).
   
   
  
positive.code: -spec gs_protocol_supported_versions() -> [gs_protocol:protocol_version()].
  gs_protocol_supported_versions() ->
      gs_protocol:supported_versions().
  
negative.code:     lfm:open(Session, FileKey, OpenType).
  
  
  -spec lfm_write(lfm_context:ctx(), integer(), binary()) ->
      {ok, lfm_context:ctx(), integer()} |{error, term()}.
  lfm_write(FileHandle, Offset, Buffer) ->
      lfm:write(FileHandle, Offset, Buffer).
  