RunnableExecutorPair(Runnable runnable, Executor executor) {
        this.runnable = runnable;
        this.executor = executor;
      }
    }
  }

  // A version of the list that uses compare and swap to manage the stack without locks.
  private static final class ExecutionListCAS {
    static final Logger log = Logger.getLogger(ExecutionListCAS.class.getName());

    private static final sun.misc.Unsafe UNSAFE;

import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A strategy for determining whether two instances are considered equivalent, and for computing
 * hash codes in a manner consistent with that equivalence. Two examples of equivalences are the
 * {@linkplain #identity() identity equivalence} and the {@linkplain #equals "equals" equivalence}.
 *
 * @author Bob Lee
 * @author Ben Yu

import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A strategy for determining whether two instances are considered equivalent, and for computing
 * hash codes in a manner consistent with that equivalence. Two examples of equivalences are the
 * {@linkplain #identity() identity equivalence} and the {@linkplain #equals "equals" equivalence}.
 *

   */
  public MapJoiner withKeyValueSeparator(String keyValueSeparator) {
    return new MapJoiner(this, keyValueSeparator);
  }

  /**
   * An object that joins map entries in the same manner as {@code Joiner} joins iterables and
   * arrays. Like {@code Joiner}, it is thread-safe and immutable.
   *
   * <p>In addition to operating on {@code Map} instances, {@code MapJoiner} can operate on {@code

    reverse(array, newFirstIndex, toIndex);
    reverse(array, fromIndex, toIndex);
  }

  /**
   * Returns an array containing each value of {@code collection}, converted to a {@code short}
   * value in the manner of {@link Number#shortValue}.
   *
   * <p>Elements are copied from the argument collection as if by {@code collection.toArray()}.
   * Calling this method is as thread-safe as calling that method.
   *

    reverse(array, newFirstIndex, toIndex);
    reverse(array, fromIndex, toIndex);
  }

  /**
   * Returns an array containing each value of {@code collection}, converted to a {@code long} value
   * in the manner of {@link Number#longValue}.
   *
   * <p>Elements are copied from the argument collection as if by {@code collection.toArray()}.
   * Calling this method is as thread-safe as calling that method.
   *