* have been newly added to {@link ConcurrentMap}! These are marked with "Since: 1.8" in the
   * {@code ConcurrentMap} documentation. They will not function correctly and it is impossible for
   * Guava to fix them until Guava is ready to <i>require</i> Java 8 for all users.
   */
  ConcurrentMap<K, V> asMap();

  /**

import com.google.errorprone.annotations.CompatibleWith;
import com.google.errorprone.annotations.DoNotMock;
import java.util.Map;
import java.util.concurrent.Callable;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.ExecutionException;
import javax.annotation.CheckForNull;

/**
 * A semi-persistent mapping from keys to values. Cache entries are manually added using {@link