Remove class-level @ElementTypesAreNonnullByDefault annotations.

They are redundant with the package-level annotations from cl/708300606. (Again, I recommend against package-level annotations in general, but they're the best option in our specific case because we are likely to have Java 8 users who use Mockito to mock some of our classes.)

For our testlib packages, I've left the usages alone: We haven't inserted a package-level annotation in those packages except for in `c.g.c.testing`. (We could pursue doing adding it, but we'd first need to insert class-level annotations in the unannotated classes.) Really, even some of the "annotated" testlib code likely hasn't been fully annotated, but that's a separate problem. Anyway, the problems we're trying to work around with package-level annotations are mostly related to mocking, and we don't expect users to mock our testlib types (which have few users of any kind to begin with). If we hear of problems, we can reevaluate. For now, we'll live with the redundant class-level annotations in `c.g.c.testing`.

(Oops, I actually had _removed_ the package-level annotation for `common.testing` in cl/708300606 instead of merely converting it from `ParametersAreNonnullByDefault`. I made that error externally only, and this CL fixes it.)

This is the next step toward [using JSpecify in Guava](jspecify/jspecify#239 (comment)).

RELNOTES=n/a
PiperOrigin-RevId: 708490780

android/guava-testlib/src/com/google/common/testing/package-info.java

@@ -18,5 +18,8 @@
  * Testing utilities. This package is a part of the open-source <a
  * href="https://github.com/google/guava">Guava</a> library.
  */
-@com.google.errorprone.annotations.CheckReturnValue
+@CheckReturnValue
+@ElementTypesAreNonnullByDefault
 package com.google.common.testing;
+
+import com.google.errorprone.annotations.CheckReturnValue;

android/guava/src/com/google/common/base/Absent.java

@@ -23,7 +23,6 @@
 
 /** Implementation of an {@link Optional} not containing a reference. */
 @GwtCompatible
-@ElementTypesAreNonnullByDefault
 final class Absent<T> extends Optional<T> {
   static final Absent<Object> INSTANCE = new Absent<>();
 

android/guava/src/com/google/common/base/AbstractIterator.java

@@ -29,7 +29,6 @@
  * reasons).
  */
 @GwtCompatible
-@ElementTypesAreNonnullByDefault
 abstract class AbstractIterator<T extends @Nullable Object> implements Iterator<T> {
   private State state = State.NOT_READY;
 

android/guava/src/com/google/common/base/Ascii.java

@@ -38,7 +38,6 @@
  * @since 7.0
  */
 @GwtCompatible
-@ElementTypesAreNonnullByDefault
 public final class Ascii {
 
   private Ascii() {}

android/guava/src/com/google/common/base/CaseFormat.java

@@ -29,7 +29,6 @@
  * @since 1.0
  */
 @GwtCompatible
-@ElementTypesAreNonnullByDefault
 public enum CaseFormat {
   /** Hyphenated variable naming convention, e.g., "lower-hyphen". */
   LOWER_HYPHEN(CharMatcher.is('-'), "-") {

android/guava/src/com/google/common/base/CharMatcher.java

@@ -61,7 +61,6 @@
  * @since 1.0
  */
 @GwtCompatible(emulated = true)
-@ElementTypesAreNonnullByDefault
 public abstract class CharMatcher implements Predicate<Character> {
   /*
    *           N777777777NO

android/guava/src/com/google/common/base/Charsets.java

@@ -33,7 +33,6 @@
  * @since 1.0
  */
 @GwtCompatible(emulated = true)
-@ElementTypesAreNonnullByDefault
 public final class Charsets {
 
   /**

android/guava/src/com/google/common/base/CommonMatcher.java

@@ -22,7 +22,6 @@
  * javadoc for details.
  */
 @GwtCompatible
-@ElementTypesAreNonnullByDefault
 abstract class CommonMatcher {
   public abstract boolean matches();
 

android/guava/src/com/google/common/base/CommonPattern.java

@@ -22,7 +22,6 @@
  * javadoc for details.
  */
 @GwtCompatible
-@ElementTypesAreNonnullByDefault
 abstract class CommonPattern {
   public abstract CommonMatcher matcher(CharSequence t);
 

android/guava/src/com/google/common/base/Converter.java

@@ -115,7 +115,6 @@
  * @since 16.0
  */
 @GwtCompatible
-@ElementTypesAreNonnullByDefault
 /*
  * 1. The type parameter is <T> rather than <T extends @Nullable> so that we can use T in the
  * doForward and doBackward methods to indicate that the parameter cannot be null. (We also take

android/guava/src/com/google/common/base/Defaults.java

@@ -28,7 +28,6 @@
  */
 @J2ktIncompatible
 @GwtIncompatible
-@ElementTypesAreNonnullByDefault
 public final class Defaults {
   private Defaults() {}
 

android/guava/src/com/google/common/base/Enums.java

@@ -35,7 +35,6 @@
  */
 @GwtIncompatible
 @J2ktIncompatible
-@ElementTypesAreNonnullByDefault
 public final class Enums {
 
   private Enums() {}

android/guava/src/com/google/common/base/Equivalence.java

@@ -40,7 +40,6 @@
  *     source-compatible</a> since 4.0)
  */
 @GwtCompatible
-@ElementTypesAreNonnullByDefault
 /*
  * The type parameter is <T> rather than <T extends @Nullable> so that we can use T in the
  * doEquivalent and doHash methods to indicate that the parameter cannot be null.

android/guava/src/com/google/common/base/ExtraObjectsMethodsForWeb.java

@@ -21,5 +21,4 @@
  * version.
  */
 @GwtCompatible(emulated = true)
-@ElementTypesAreNonnullByDefault
 abstract class ExtraObjectsMethodsForWeb {}

android/guava/src/com/google/common/base/FinalizablePhantomReference.java

@@ -32,7 +32,6 @@
  */
 @J2ktIncompatible
 @GwtIncompatible
-@ElementTypesAreNonnullByDefault
 public abstract class FinalizablePhantomReference<T> extends PhantomReference<T>
     implements FinalizableReference {
   /**

android/guava/src/com/google/common/base/FinalizableReference.java

@@ -28,7 +28,6 @@
 @DoNotMock("Use an instance of one of the Finalizable*Reference classes")
 @J2ktIncompatible
 @GwtIncompatible
-@ElementTypesAreNonnullByDefault
 public interface FinalizableReference {
   /**
    * Invoked on a background thread after the referent has been garbage collected unless security

android/guava/src/com/google/common/base/FinalizableReferenceQueue.java

@@ -138,7 +138,6 @@
  */
 @J2ktIncompatible
 @GwtIncompatible
-@ElementTypesAreNonnullByDefault
 public class FinalizableReferenceQueue implements Closeable {
   /*
    * The Finalizer thread keeps a phantom reference to this object. When the client (for example, a

android/guava/src/com/google/common/base/FinalizableSoftReference.java

@@ -30,7 +30,6 @@
  */
 @J2ktIncompatible
 @GwtIncompatible
-@ElementTypesAreNonnullByDefault
 public abstract class FinalizableSoftReference<T> extends SoftReference<T>
     implements FinalizableReference {
   /**

android/guava/src/com/google/common/base/FinalizableWeakReference.java

@@ -30,7 +30,6 @@
  */
 @J2ktIncompatible
 @GwtIncompatible
-@ElementTypesAreNonnullByDefault
 public abstract class FinalizableWeakReference<T> extends WeakReference<T>
     implements FinalizableReference {
   /**

android/guava/src/com/google/common/base/Function.java

@@ -44,7 +44,6 @@
  * @since 2.0
  */
 @GwtCompatible
-@ElementTypesAreNonnullByDefault
 public interface Function<F extends @Nullable Object, T extends @Nullable Object> {
   /**
    * Returns the result of applying this function to {@code input}. This method is <i>generally

android/guava/src/com/google/common/base/FunctionalEquivalence.java

@@ -28,7 +28,6 @@
  * @since 10.0
  */
 @GwtCompatible
-@ElementTypesAreNonnullByDefault
 final class FunctionalEquivalence<F, T> extends Equivalence<F> implements Serializable {
 
   private static final long serialVersionUID = 0;

android/guava/src/com/google/common/base/Functions.java

@@ -38,7 +38,6 @@
  * @since 2.0
  */
 @GwtCompatible
-@ElementTypesAreNonnullByDefault
 public final class Functions {
   private Functions() {}
 

android/guava/src/com/google/common/base/IgnoreJRERequirement.java

@@ -26,5 +26,4 @@
  * <p>Each package's copy of this annotation needs to be listed in our {@code pom.xml}.
  */
 @Target({METHOD, CONSTRUCTOR, TYPE})
-@ElementTypesAreNonnullByDefault
 @interface IgnoreJRERequirement {}

android/guava/src/com/google/common/base/Internal.java

@@ -21,7 +21,6 @@
 /** This class is for {@code com.google.common.base} use only! */
 @J2ktIncompatible
 @GwtIncompatible // java.time.Duration
-@ElementTypesAreNonnullByDefault
 final class Internal {
 
   /**

android/guava/src/com/google/common/base/Java8Compatibility.java

@@ -24,7 +24,6 @@
  */
 @J2ktIncompatible
 @GwtIncompatible
-@ElementTypesAreNonnullByDefault
 final class Java8Compatibility {
   static void clear(Buffer b) {
     b.clear();

android/guava/src/com/google/common/base/JdkPattern.java

@@ -20,7 +20,6 @@
 import java.util.regex.Pattern;
 
 /** A regex pattern implementation which is backed by the {@link Pattern}. */
-@ElementTypesAreNonnullByDefault
 @GwtIncompatible
 final class JdkPattern extends CommonPattern implements Serializable {
   private final Pattern pattern;

android/guava/src/com/google/common/base/Joiner.java

@@ -65,7 +65,6 @@
  * @since 2.0
  */
 @GwtCompatible
-@ElementTypesAreNonnullByDefault
 public class Joiner {
   /** Returns a joiner which automatically places {@code separator} between consecutive elements. */
   public static Joiner on(String separator) {

android/guava/src/com/google/common/base/MoreObjects.java

@@ -36,7 +36,6 @@
  * @since 18.0 (since 2.0 as {@code Objects})
  */
 @GwtCompatible
-@ElementTypesAreNonnullByDefault
 public final class MoreObjects {
   /**
    * Returns the first of two given parameters that is not {@code null}, if either is, or otherwise

android/guava/src/com/google/common/base/NullnessCasts.java

@@ -20,7 +20,6 @@
 
 /** A utility method to perform unchecked casts to suppress errors produced by nullness analyses. */
 @GwtCompatible
-@ElementTypesAreNonnullByDefault
 final class NullnessCasts {
   /**
    * Accepts a {@code @Nullable T} and returns a plain {@code T}, without performing any check that

android/guava/src/com/google/common/base/Objects.java

@@ -30,7 +30,6 @@
  * @since 2.0
  */
 @GwtCompatible
-@ElementTypesAreNonnullByDefault
 public final class Objects extends ExtraObjectsMethodsForWeb {
   private Objects() {}
 

android/guava/src/com/google/common/base/Optional.java

@@ -84,7 +84,6 @@
  */
 @DoNotMock("Use Optional.of(value) or Optional.absent()")
 @GwtCompatible(serializable = true)
-@ElementTypesAreNonnullByDefault
 public abstract class Optional<T> implements Serializable {
   /**
    * Returns an {@code Optional} instance with no contained reference.

android/guava/src/com/google/common/base/PairwiseEquivalence.java

@@ -21,7 +21,6 @@
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 @GwtCompatible(serializable = true)
-@ElementTypesAreNonnullByDefault
 final class PairwiseEquivalence<E, T extends @Nullable E> extends Equivalence<Iterable<T>>
     implements Serializable {
   final Equivalence<E> elementEquivalence;

android/guava/src/com/google/common/base/PatternCompiler.java

@@ -23,7 +23,6 @@
  * java.util.ServiceLoader} mechanism.
  */
 @GwtIncompatible
-@ElementTypesAreNonnullByDefault
 interface PatternCompiler {
   /**
    * Compiles the given pattern.

android/guava/src/com/google/common/base/Platform.java

@@ -26,7 +26,6 @@
  * @author Jesse Wilson
  */
 @GwtCompatible(emulated = true)
-@ElementTypesAreNonnullByDefault
 final class Platform {
   private static final PatternCompiler patternCompiler = loadPatternCompiler();
 

android/guava/src/com/google/common/base/Preconditions.java

@@ -114,7 +114,6 @@
  * @since 2.0
  */
 @GwtCompatible
-@ElementTypesAreNonnullByDefault
 public final class Preconditions {
   private Preconditions() {}
 

android/guava/src/com/google/common/base/Predicate.java

@@ -45,7 +45,6 @@
  * @since 2.0
  */
 @GwtCompatible
-@ElementTypesAreNonnullByDefault
 public interface Predicate<T extends @Nullable Object> {
   /**
    * Returns the result of applying this predicate to {@code input} (Java 8+ users, see notes in the

android/guava/src/com/google/common/base/Predicates.java

@@ -40,7 +40,6 @@
  * @since 2.0
  */
 @GwtCompatible(emulated = true)
-@ElementTypesAreNonnullByDefault
 public final class Predicates {
   private Predicates() {}
 

android/guava/src/com/google/common/base/Present.java

@@ -23,7 +23,6 @@
 
 /** Implementation of an {@link Optional} containing a reference. */
 @GwtCompatible
-@ElementTypesAreNonnullByDefault
 final class Present<T> extends Optional<T> {
   private final T reference;
 

android/guava/src/com/google/common/base/SmallCharMatcher.java

@@ -26,7 +26,6 @@
  * @author Christopher Swenson
  */
 @GwtIncompatible // no precomputation is done in GWT
-@ElementTypesAreNonnullByDefault
 final class SmallCharMatcher extends NamedFastMatcher {
   static final int MAX_SIZE = 1023;
   private final char[] table;

android/guava/src/com/google/common/base/Splitter.java

@@ -99,7 +99,6 @@
  * @since 1.0
  */
 @GwtCompatible(emulated = true)
-@ElementTypesAreNonnullByDefault
 public final class Splitter {
   private final CharMatcher trimmer;
   private final boolean omitEmptyStrings;

android/guava/src/com/google/common/base/StandardSystemProperty.java

@@ -26,7 +26,6 @@
  */
 @J2ktIncompatible
 @GwtIncompatible // java.lang.System#getProperty
-@ElementTypesAreNonnullByDefault
 public enum StandardSystemProperty {
 
   /** Java Runtime Environment version. */

android/guava/src/com/google/common/base/Stopwatch.java

@@ -96,7 +96,6 @@
  */
 @GwtCompatible(emulated = true)
 @SuppressWarnings("GoodTime") // lots of violations
-@ElementTypesAreNonnullByDefault
 public final class Stopwatch {
   private final Ticker ticker;
   private boolean isRunning;

android/guava/src/com/google/common/base/Strings.java

@@ -32,7 +32,6 @@
  * @since 3.0
  */
 @GwtCompatible
-@ElementTypesAreNonnullByDefault
 public final class Strings {
   private Strings() {}
 

android/guava/src/com/google/common/base/Supplier.java

@@ -45,7 +45,6 @@
  * @since 2.0
  */
 @GwtCompatible
-@ElementTypesAreNonnullByDefault
 public interface Supplier<T extends @Nullable Object> {
   /**
    * Retrieves an instance of the appropriate type. The returned object may or may not be a new

android/guava/src/com/google/common/base/Suppliers.java

@@ -41,7 +41,6 @@
  * @since 2.0
  */
 @GwtCompatible(emulated = true)
-@ElementTypesAreNonnullByDefault
 public final class Suppliers {
   private Suppliers() {}
 

android/guava/src/com/google/common/base/Throwables.java

@@ -46,7 +46,6 @@
  * @since 1.0
  */
 @GwtCompatible(emulated = true)
-@ElementTypesAreNonnullByDefault
 public final class Throwables {
   private Throwables() {}
 

android/guava/src/com/google/common/base/Ticker.java

@@ -28,7 +28,6 @@
  *     source-compatible</a> since 9.0)
  */
 @GwtCompatible
-@ElementTypesAreNonnullByDefault
 public abstract class Ticker {
   /** Constructor for use by subclasses. */
   protected Ticker() {}

android/guava/src/com/google/common/base/Utf8.java

@@ -36,7 +36,6 @@
  * @since 16.0
  */
 @GwtCompatible(emulated = true)
-@ElementTypesAreNonnullByDefault
 public final class Utf8 {
   /**
    * Returns the number of bytes in the UTF-8-encoded form of {@code sequence}. For a string, this

android/guava/src/com/google/common/base/Verify.java

@@ -88,7 +88,6 @@
  * @since 17.0
  */
 @GwtCompatible
-@ElementTypesAreNonnullByDefault
 public final class Verify {
   /**
    * Ensures that {@code expression} is {@code true}, throwing a {@code VerifyException} with no

android/guava/src/com/google/common/base/VerifyException.java

@@ -25,7 +25,6 @@
  * @since 17.0
  */
 @GwtCompatible
-@ElementTypesAreNonnullByDefault
 public class VerifyException extends RuntimeException {
   /** Constructs a {@code VerifyException} with no message. */
   public VerifyException() {}