return false;
      }

      @Override
      public boolean removeAll(Collection<?> collection) {
        return removeAllKeys(unfiltered, predicate, collection);
      }

      @Override
      public boolean retainAll(Collection<?> collection) {
        return retainAllKeys(unfiltered, predicate, collection);
      }

      @Override
      public @Nullable Object[] toArray() {

        return false;
      }

      @Override
      public boolean removeAll(Collection<?> collection) {
        return removeAllKeys(unfiltered, predicate, collection);
      }

      @Override
      public boolean retainAll(Collection<?> collection) {
        return retainAllKeys(unfiltered, predicate, collection);
      }

      @Override
      public @Nullable Object[] toArray() {

   *     to primitives
   * @throws NullPointerException if {@code collection} or any of its elements is null
   * @since 1.0 (parameter was {@code Collection<Float>} before 12.0)
   */
  public static float[] toArray(Collection<? extends Number> collection) {
    if (collection instanceof FloatArrayAsList) {
      return ((FloatArrayAsList) collection).toFloatArray();
    }

   *     to primitives
   * @throws NullPointerException if {@code collection} or any of its elements is null
   * @since 1.0 (parameter was {@code Collection<Double>} before 12.0)
   */
  public static double[] toArray(Collection<? extends Number> collection) {
    if (collection instanceof DoubleArrayAsList) {
      return ((DoubleArrayAsList) collection).toDoubleArray();
    }

   *     to primitives
   * @throws NullPointerException if {@code collection} or any of its elements is null
   * @since 1.0 (parameter was {@code Collection<Float>} before 12.0)
   */
  public static float[] toArray(Collection<? extends Number> collection) {
    if (collection instanceof FloatArrayAsList) {
      return ((FloatArrayAsList) collection).toFloatArray();
    }

 */

package com.google.common.collect.testing;

import static java.util.Arrays.asList;

import com.google.common.annotations.GwtCompatible;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Set;
import org.checkerframework.checker.nullness.qual.NonNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**

import com.google.common.annotations.GwtCompatible;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * To be implemented by test generators of things that can contain elements. Such things include
 * both {@link Collection} and {@link Map}; since there isn't an established collective noun that

import com.google.common.collect.Multimap;
import com.google.common.collect.testing.features.CollectionSize;
import com.google.common.collect.testing.features.MapFeature;
import java.util.Collection;
import org.junit.Ignore;

/**
 * Tests for {@link Multimap#removeAll(Object)}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible

  public Object[] toArray() {
    /*
     * ObjectArrays.toArrayImpl returns `@Nullable Object[]` rather than `Object[]` but only because
     * it can be used with collections that may contain null. This collection is a collection of
     * non-null elements, so we can treat it as a plain `Object[]`.
     */
    @SuppressWarnings("nullness")
    Object[] result = ObjectArrays.toArrayImpl(this);
    return result;
  }

        "[" + e0() + "]",
        collection.toString());
  }

  @CollectionSize.Require(SEVERAL)
  @CollectionFeature.Require(value = KNOWN_ORDER, absent = NON_STANDARD_TOSTRING)
  public void testToString_sizeSeveral() {
    String expected = copyToList(getOrderedElements()).toString();
    assertEquals("collection.toString() incorrect", expected, collection.toString());
  }

  @CollectionSize.Require(absent = ZERO)