docs: public ApiResponse<Integer> postCharactersCharacterIdMailLabelsWithHttpInfo(Integer characterId, String datasource,
              String token, MailLabelSimple mailLabelSimple) throws ApiException {
          com.squareup.okhttp.Call call = postCharactersCharacterIdMailLabelsValidateBeforeCall(characterId, datasource,
                  token, mailLabelSimple, null);
          Type localVarReturnType = new TypeToken<Integer>() {
          }.getType();
          return apiClient.execute(call, localVarReturnType);
      }