return this;
  }

  /**
   * Sets the backing {@link ThreadFactory} for new threads created with this ThreadFactory. Threads
   * will be created by invoking #newThread(Runnable) on this backing {@link ThreadFactory}.
   *
   * @param backingThreadFactory the backing {@link ThreadFactory} which will be delegated to during
   *     thread creation.
   * @return this for the builder pattern

    )
  }

  class RealBackend(
    threadFactory: ThreadFactory,
  ) : Backend {
    val executor =
      ThreadPoolExecutor(
        // corePoolSize:
        0,
        // maximumPoolSize:
        Int.MAX_VALUE,
        // keepAliveTime:
        60L,
        TimeUnit.SECONDS,
        SynchronousQueue(),
        threadFactory,
      )

    override fun nanoTime() = System.nanoTime()

import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.locks.ReentrantLock;
import java.util.logging.Level;
import org.jspecify.annotations.Nullable;

/**

import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.locks.ReentrantLock;
import java.util.logging.Level;
import org.jspecify.annotations.Nullable;

/**