import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.collect.Multisets.UnmodifiableMultiset;
import com.google.errorprone.annotations.concurrent.LazyInit;
import java.util.Comparator;
import java.util.NavigableSet;
import org.jspecify.annotations.Nullable;

/**

 */

package com.google.common.collect.testing.testers;

import static com.google.common.collect.testing.Helpers.getMethod;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import java.lang.reflect.Method;
import org.junit.Ignore;

/**
 * Tests {@link java.util.List#hashCode}.
 *

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect.testing.testers;

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.testing.AbstractCollectionTester;
import java.util.Set;
import org.junit.Ignore;

/**
 * @author George van den Driessche
 */
@GwtCompatible

 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

package com.google.common.base;

import com.google.common.annotations.GwtIncompatible;
import com.google.errorprone.annotations.RestrictedApi;

/**
 * Pluggable interface for compiling a regex pattern. By default this package uses the {@code

 * library.
 *
 * @author Charles Fry
 */
@CheckReturnValue
@NullMarked
package com.google.common.cache;

import com.google.errorprone.annotations.CheckReturnValue;

 * the License.
 */

package com.google.common.util.concurrent;

import com.google.common.annotations.GwtCompatible;
import java.util.concurrent.Future;
import org.jspecify.annotations.Nullable;

/**
 * Transforms a value, possibly asynchronously. For an example usage and more information, see

 * the License.
 */

package com.google.common.util.concurrent;

import com.google.common.annotations.GwtCompatible;
import java.util.concurrent.Future;
import org.jspecify.annotations.Nullable;

/**
 * Computes a value, possibly asynchronously. For an example usage and more information, see {@link

import com.google.common.annotations.GwtCompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Objects;
import java.util.function.BiPredicate;
import java.util.stream.Collector;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

### Invalid Return Type Annotations { #invalid-return-type-annotations }

But when you return some other arbitrary object that is not a valid Pydantic type (e.g. a database object) and you annotate it like that in the function, FastAPI will try to create a Pydantic response model from that type annotation, and will fail.

import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_ITERATOR_REMOVE;
import static java.util.Arrays.asList;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.collect.testing.IteratorTester;
import com.google.common.collect.testing.features.CollectionFeature;