code: @Override
      public void unregister(Module module) {
          if (module == null) {
              // May happen on departure.
              return;
          }
          LOGGER.info("Removing Jackson module {}", module.getModuleName());
          synchronized (lock) {
              if (modules.remove(module)) {
                  rebuildMappers();
              }
          }
      }
docs: Un-registers a JSON Module.
  
  @param module the module