code: @NonNull
      public JsonProcessor lookup() {
          JsonProcessor registeredJsonProcessor = this.registeredJsonProcessor;
          if (registeredJsonProcessor != null) {
              return registeredJsonProcessor;
          }
  
          if (!init) {
              synchronized (this) {
                  if (!init) {
                      lookedJsonProcessor = lookupInClasspath();
                      init = true;
                  }
              }
          }
  
          if (lookedJsonProcessor != null) {
              return lookedJsonProcessor;
          }
          throw new JsonProcessorNotFoundException("Json Provider not found");
      }
docs: Find one json provider.
  
  @throws JsonProcessorNotFoundException if no json provider found