private var coordinatorWaiting = false
  private var coordinatorWakeUpAt = 0L

  /**
   * When we need a new thread to run tasks, we call [Backend.execute]. A few microseconds later we
   * expect a newly-started thread to call [Runnable.run]. We shouldn't request new threads until
   * the already-requested ones are in service, otherwise we might create more threads than we need.
   *

          return var;
        }
        Type[] resolvedBounds = new TypeResolver(forDependants).resolveTypes(bounds);
        /*
         * We'd like to simply create our own TypeVariable with the newly resolved bounds. There's
         * just one problem: Under all the JDK versions that we support (though *not* under
         * Android), the built-in TypeVariable's equals() method doesn't recognize instances of our

          return var;
        }
        Type[] resolvedBounds = new TypeResolver(forDependants).resolveTypes(bounds);
        /*
         * We'd like to simply create our own TypeVariable with the newly resolved bounds. There's
         * just one problem: Under all the JDK versions that we support (though *not* under
         * Android), the built-in TypeVariable's equals() method doesn't recognize instances of our

 * {@link #writeTo} and {@link #readFrom} methods. Both serialized forms will continue to be
 * supported by future versions of this library. However, serial forms generated by newer versions
 * of the code may not be readable by older versions of the code (e.g., a serialized Bloom filter
 * generated today may <i>not</i> be readable by a binary that was compiled 6 months ago).
 *

        }
        final AcknowledgedResponse response = builder.execute().actionGet(fessConfig.getIndexIndicesTimeout());
        return response.isAcknowledged();
    }

    /**
     * Creates aliases for a newly created index.
     *
     * @param index            the index configuration name
     * @param createdIndexName the actual index name that was created
     */