code: @RequestMapping(method = RequestMethod.POST)
      @Transactional
      public Callable<ResponseEntity<JsonNode>> post(@RequestBody String input) throws IOException {
          return () -> {
              // Gets the components
              Request request = objectMapper.readValue(input, Request.class);
              // Variables must not be null
              request = request.withVariables();
              // Runs the query
              return ResponseEntity.ok(
                      requestAsJson(request)
              );
          };
      }
docs: POST end point