* while adding a new pair.
 *
 * <p>This class is not threadsafe when any concurrent operations update the multimap, even if the
 * underlying map and {@link #createCollection()} method return threadsafe classes. Concurrent read
 * operations will work correctly. To allow concurrent update operations, wrap your multimap with a
 * call to {@link Multimaps#synchronizedMultimap}.
 *

 *
 * <ul>
 *   <li><b>Finite:</b> Many operations, such as {@link #length()} and {@link #read()}, will either
 *       block indefinitely or fail if the source creates an infinite reader.
 *   <li><b>Non-destructive:</b> A <i>destructive</i> reader will consume or otherwise alter the
 *       source as they are read from it. A source that provides such readers will not be reusable,

 * variety of sequences of the {@link Iterator#next}, {@link Iterator#hasNext} and {@link
 * Iterator#remove} operations. This utility takes the brute-force approach of trying <i>all</i>
 * possible sequences of these operations, up to a given number of steps. So, if the caller
 * specifies to use <i>n</i> steps, a total of <i>3^n</i> tests are actually performed.
 *

  @Override
  public int count(@CheckForNull Object element) {
    Count frequency = Maps.safeGet(backingMap, element);
    return (frequency == null) ? 0 : frequency.get();
  }

  // Optional Operations - Modification Operations

  /**
   * {@inheritDoc}
   *
   * @throws IllegalArgumentException if the call would result in more than {@link
   *     Integer#MAX_VALUE} occurrences of {@code element} in this multiset.

                  }
                })
            .named("Lists.transform, random access, no nulls")
            .withFeatures(
                CollectionSize.ANY,
                ListFeature.REMOVE_OPERATIONS,
                CollectionFeature.SERIALIZABLE,
                CollectionFeature.ALLOWS_NULL_QUERIES)
            .createTestSuite());

    suite.addTest(
        ListTestSuiteBuilder.using(

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.Map.Entry;
import java.util.concurrent.ConcurrentMap;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@code putIfAbsent} operations on a concurrent map. Can't be
 * invoked directly; please see {@link
 * com.google.common.collect.testing.ConcurrentMapTestSuiteBuilder}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible

        }
      }
      return list;
    }

    // Modification Operations

    /**
     * Adds a number of occurrences of the specified element to this multiset.
     *
     * @param element the element to add
     * @param occurrences the number of occurrences to add
     * @return the previous count of the element before the operation; possibly zero

import com.google.common.annotations.GwtCompatible;

/**
 * An object that can perform a {@link #tearDown} operation.
 *
 * @author Kevin Bourrillion
 * @since 10.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public interface TearDown {
  /**
   * Performs a <b>single</b> tear-down operation. See test-libraries-for-java's {@code
   * com.google.common.testing.junit3.TearDownTestCase} and {@code

   */
  GENERAL_PURPOSE(SUPPORTS_ADD, SUPPORTS_REMOVE, SUPPORTS_ITERATOR_REMOVE),

  /** Features supported by collections where only removal is allowed. */
  REMOVE_OPERATIONS(SUPPORTS_REMOVE, SUPPORTS_ITERATOR_REMOVE),

  SERIALIZABLE,
  SERIALIZABLE_INCLUDING_VIEWS(SERIALIZABLE),

  SUBSET_VIEW,
  DESCENDING_VIEW,

  /**

        // of executing. Don't null out the latestTaskQueue field, because the work done here
        // may have scheduled more operations on another thread, and if those operations then
        // trigger reentrant calls that thread will have updated the latestTaskQueue field, and
        // we'd be interfering with their operation.
        executingTaskQueue.thread = null;
      }
    }

    private boolean trySetStarted() {