public void invokeBucketReadHook() {
    Runnable r = bucketReadHook;
    if (r != null) {
      setBucketReadHook(null);
      r.run();
    }
  }
invokes a test hook, if it was installed, and removes it.
geode-core/src/main/java/org/apache/geode/internal/cache/PartitionedRegionDataStore.java