public Builder useShutdownNow() {
      useShutdown = false;
      useShutdownNow = true;
      return this;
    }
Enables invocation of {@code shutdownNow} during {@code tearDown}. Default is enabled.

@return a reference to this Builder
geode-dunit/src/main/java/org/apache/geode/test/dunit/rules/DistributedExecutorServiceRule.java