code: @Override @DefinedBy(Api.COMPILER)
      public void close() throws IOException {
          if (deferredCloseTimeout > 0) {
              deferredClose();
              return;
          }
  
          locations.close();
          for (Container container: containers.values()) {
              container.close();
          }
          containers.clear();
          contentCache.clear();
      }
docs: Close the JavaFileManager, releasing resources.