Remove explicit visibilities from effectively private members.

And add `@Keep` to cases in which we don't want that to happen. (When such members already had `@SuppressWarnings("unused")`, I removed the latter.)

I have forgotten whether there are reasons to prefer `@Keep` (which is retained all the way to `RUNTIME`) over `@SuppressWarnings` (which has only `SOURCE` retention). (Extra retention could be either good or bad.) I might expect `@SuppressWarnings` to be recognized by _more_ tools (mainly "non-Google" tools like IntelliJ?). Probably part of the reason for `@Keep` is to use it as a _meta-annotation_, and we're not doing that here. I guess "`@Keep`" is shorter :) Probably most relevant here, `@Keep` suggests "Do not touch this at all" (including possibly things like "Don't make it `final`," which may or may not be desirable in our various usages), whereas `@SuppressWarnings("unused")` at least doesn't suggest that quite as much?

Prompted by google/error-prone#5156.

RELNOTES=n/a
PiperOrigin-RevId: 782899232

Author: cpovirk

android/guava-testlib/src/com/google/common/collect/testing/PerCollectionSizeTestSuiteBuilder.java

@@ -126,7 +126,7 @@ private static final class OneSizeTestSuiteBuilder<T, E>
     private final List<Class<? extends AbstractTester>> testers;
 
     @SuppressWarnings("rawtypes") // class literals
-    public OneSizeTestSuiteBuilder(List<Class<? extends AbstractTester>> testers) {
+    OneSizeTestSuiteBuilder(List<Class<? extends AbstractTester>> testers) {
       this.testers = testers;
     }
 

android/guava-testlib/src/com/google/common/collect/testing/google/MultimapTestSuiteBuilder.java

@@ -314,7 +314,7 @@ private static class AsMapGenerator<K, V, M extends Multimap<K, V>>
       implements TestMapGenerator<K, Collection<V>>, DerivedGenerator {
     private final OneSizeTestContainerGenerator<M, Entry<K, V>> multimapGenerator;
 
-    public AsMapGenerator(OneSizeTestContainerGenerator<M, Entry<K, V>> multimapGenerator) {
+    AsMapGenerator(OneSizeTestContainerGenerator<M, Entry<K, V>> multimapGenerator) {
       this.multimapGenerator = multimapGenerator;
     }
 
@@ -638,8 +638,7 @@ private static class ReserializedMultimapGenerator<K, V, M extends Multimap<K, V
       implements TestMultimapGenerator<K, V, M> {
     private final OneSizeTestContainerGenerator<M, Entry<K, V>> multimapGenerator;
 
-    public ReserializedMultimapGenerator(
-        OneSizeTestContainerGenerator<M, Entry<K, V>> multimapGenerator) {
+    ReserializedMultimapGenerator(OneSizeTestContainerGenerator<M, Entry<K, V>> multimapGenerator) {
       this.multimapGenerator = multimapGenerator;
     }
 

android/guava-testlib/src/com/google/common/collect/testing/google/SetGenerators.java

@@ -412,7 +412,7 @@ public List<Integer> order(List<Integer> insertionOrder) {
 
   private abstract static class AbstractContiguousSetGenerator
       extends TestIntegerSortedSetGenerator {
-    protected final ContiguousSet<Integer> checkedCreate(SortedSet<Integer> elementsSet) {
+    final ContiguousSet<Integer> checkedCreate(SortedSet<Integer> elementsSet) {
       List<Integer> elements = new ArrayList<>(elementsSet);
       /*
        * A ContiguousSet can't have holes. If a test demands a hole, it should be changed so that it

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

@@ -631,7 +631,7 @@ public boolean isExpectedType(Throwable cause) {
       }
     };
 
-    public abstract boolean isExpectedType(Throwable cause);
+    abstract boolean isExpectedType(Throwable cause);
   }
 
   private static boolean annotatedTypeExists() {

android/guava-testlib/test/com/google/common/collect/testing/features/FeatureUtilTest.java

@@ -36,6 +36,7 @@
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.testing.features.FeatureUtilTest.ExampleFeature.NotTesterAnnotation;
 import com.google.common.collect.testing.features.FeatureUtilTest.ExampleFeature.Require;
+import com.google.errorprone.annotations.Keep;
 import java.lang.annotation.Inherited;
 import java.lang.annotation.Retention;
 import java.lang.reflect.Method;
@@ -175,6 +176,7 @@ class Tester {}
   public void testBuildTesterRequirements_class_present_method_present() throws Exception {
     @Require(IMPLIES_BAR)
     class Tester {
+      @Keep
       @Require(IMPLIES_IMPLIES_FOO)
       public void test() {}
     }
@@ -189,6 +191,7 @@ public void test() {}
   public void testBuildTesterRequirements_class_absent_method_absent() throws Exception {
     @Require(absent = IMPLIES_BAR)
     class Tester {
+      @Keep
       @Require(absent = IMPLIES_IMPLIES_FOO)
       public void test() {}
     }
@@ -202,6 +205,7 @@ public void test() {}
   public void testBuildTesterRequirements_class_present_method_absent() throws Exception {
     @Require(IMPLIES_IMPLIES_FOO)
     class Tester {
+      @Keep
       @Require(absent = IMPLIES_IMPLIES_FOO_AND_IMPLIES_BAR)
       public void test() {}
     }
@@ -217,6 +221,7 @@ public void test() {}
   public void testBuildTesterRequirements_class_absent_method_present() throws Exception {
     @Require(absent = IMPLIES_IMPLIES_FOO_AND_IMPLIES_BAR)
     class Tester {
+      @Keep
       @Require(IMPLIES_IMPLIES_FOO)
       public void test() {}
     }
@@ -267,6 +272,7 @@ class Tester {}
   public void testBuildTesterRequirements_methodClassConflict() throws Exception {
     @Require(IMPLIES_FOO)
     class Tester {
+      @Keep
       @Require(absent = FOO)
       public void test() {}
     }
@@ -301,6 +307,7 @@ class Tester {}
 
   public void testGetTesterAnnotations_method() throws Exception {
     class Tester {
+      @Keep
       @Require
       @NotTesterAnnotation
       public void test() {}

android/guava-testlib/test/com/google/common/testing/anotherpackage/ForwardingWrapperTesterTest.java

@@ -320,7 +320,7 @@ private interface Adder {
   private static class ForwardingArithmetic implements Arithmetic {
     private final Arithmetic arithmetic;
 
-    public ForwardingArithmetic(Arithmetic arithmetic) {
+    ForwardingArithmetic(Arithmetic arithmetic) {
       this.arithmetic = arithmetic;
     }
 
@@ -455,7 +455,7 @@ void foo(
   private static class ParameterTypesDifferentForwarder implements ParameterTypesDifferent {
     private final ParameterTypesDifferent delegate;
 
-    public ParameterTypesDifferentForwarder(ParameterTypesDifferent delegate) {
+    ParameterTypesDifferentForwarder(ParameterTypesDifferent delegate) {
       this.delegate = delegate;
     }
 

android/guava-tests/benchmark/com/google/common/collect/ConcurrentHashMultisetBenchmark.java

@@ -175,7 +175,7 @@ private static final class OldConcurrentHashMultiset<E> extends AbstractMultiset
      * Creates a new, empty {@code OldConcurrentHashMultiset} using the default initial capacity,
      * load factor, and concurrency settings.
      */
-    public static <E> OldConcurrentHashMultiset<E> create() {
+    static <E> OldConcurrentHashMultiset<E> create() {
       return new OldConcurrentHashMultiset<E>(new ConcurrentHashMap<E, Integer>());
     }
 
@@ -351,7 +351,7 @@ private int removeAllOccurrences(@Nullable Object element) {
      * @param occurrences the number of occurrences of {@code element} to remove
      * @return {@code true} if the removal was possible (including if {@code occurrences} is zero)
      */
-    public boolean removeExactly(@Nullable Object element, int occurrences) {
+    boolean removeExactly(@Nullable Object element, int occurrences) {
       if (occurrences == 0) {
         return true;
       }

android/guava-tests/benchmark/com/google/common/hash/MessageDigestAlgorithmBenchmark.java

@@ -69,7 +69,7 @@ public byte[] hash(Algorithm algorithm, byte[] input) {
     };
     ;
 
-    public abstract byte[] hash(Algorithm algorithm, byte[] input);
+    abstract byte[] hash(Algorithm algorithm, byte[] input);
   }
 
   private enum Algorithm {
@@ -87,15 +87,15 @@ private enum Algorithm {
       this.hashFn = hashFn;
     }
 
-    public MessageDigest getMessageDigest() {
+    MessageDigest getMessageDigest() {
       try {
         return MessageDigest.getInstance(algorithmName);
       } catch (NoSuchAlgorithmException e) {
         throw new AssertionError(e);
       }
     }
 
-    public HashFunction getHashFunction() {
+    HashFunction getHashFunction() {
       return hashFn;
     }
   }

android/guava-tests/benchmark/com/google/common/math/ApacheBenchmark.java

@@ -99,21 +99,21 @@ public boolean noMulOverflow(long a, long b) {
       }
     };
 
-    public abstract double factorialDouble(int n);
+    abstract double factorialDouble(int n);
 
-    public abstract long binomialCoefficient(int n, int k);
+    abstract long binomialCoefficient(int n, int k);
 
-    public abstract int gcdInt(int a, int b);
+    abstract int gcdInt(int a, int b);
 
-    public abstract long gcdLong(long a, long b);
+    abstract long gcdLong(long a, long b);
 
-    public abstract boolean noAddOverflow(int a, int b);
+    abstract boolean noAddOverflow(int a, int b);
 
-    public abstract boolean noAddOverflow(long a, long b);
+    abstract boolean noAddOverflow(long a, long b);
 
-    public abstract boolean noMulOverflow(int a, int b);
+    abstract boolean noMulOverflow(int a, int b);
 
-    public abstract boolean noMulOverflow(long a, long b);
+    abstract boolean noMulOverflow(long a, long b);
   }
 
   private final int[] factorials = new int[ARRAY_SIZE];

android/guava-tests/test/com/google/common/base/ConverterTest.java

@@ -112,7 +112,7 @@ public void testApply() {
   private static class StringWrapper {
     private final String value;
 
-    public StringWrapper(String value) {
+    StringWrapper(String value) {
       this.value = value;
     }
   }