code: protected boolean handleJsonBody(ActionRuntime runtime, VirtualForm virtualForm) {
          final ActionFormMeta formMeta = virtualForm.getFormMeta();
          if (formMeta.isJsonBodyMapping()) {
              if (formMeta.isRootSymbolForm()) {
                  mappingJsonBody(runtime, virtualForm, prepareJsonFromRequestBody(virtualForm));
              } else if (formMeta.isTypedListForm()) {
                  mappingListJsonBody(runtime, virtualForm, prepareJsonFromRequestBody(virtualForm));
              }
              // basically no way here (but no exception just in case)
          }
          return false;
      }
docs: =========