import java.util.function.Supplier;
import java.util.stream.Collector;
import org.jspecify.annotations.Nullable;

/** Collectors utilities for {@code common.collect.Table} internals. */
@GwtCompatible
@IgnoreJRERequirement // used only from APIs with Java 8 types in them
final class TableCollectors {

  static <T extends @Nullable Object, R, C, V>
      Collector<T, ?, ImmutableTable<R, C, V>> toImmutableTable(

        collector.setSource("SOURCE_PROBLEM2");
        collector.add(null, "PROBLEM2", -1, -1, null);

        collector.setSource("SOURCE_PROBLEM3");
        collector.add(null, "PROBLEM3", -1, -1, null);

        assertEquals("", collector.getProblems().get(0).getSource());
        assertEquals("SOURCE_PROBLEM2", collector.getProblems().get(1).getSource());

    Collector<Entry<AnEnum, Integer>, ?, ImmutableMap<AnEnum, Integer>> collector =
        toImmutableEnumMap(Entry::getKey, Entry::getValue);
    assertThrows(
        IllegalArgumentException.class,
        () -> Stream.of(mapEntry(AnEnum.A, 1), mapEntry(AnEnum.A, 11)).collect(collector));
  }

  public void testToImmutableMapMerging() {

     */
    @Nonnull
    Stream<P> problems(BuilderProblem.Severity severity);

    /**
     * Creates an "empty" problem collector that doesn't store any problems.
     *
     * @param <P> the type of problem
     * @return an empty problem collector
     */
    @Nonnull
    static <P extends BuilderProblem> ProblemCollector<P> empty() {
        return new ProblemCollector<>() {

import java.util.function.Supplier;
import java.util.stream.Collector;
import org.jspecify.annotations.Nullable;

/** Collectors utilities for {@code common.collect.Table} internals. */
@GwtCompatible
final class TableCollectors {

  static <T extends @Nullable Object, R, C, V>
      Collector<T, ?, ImmutableTable<R, C, V>> toImmutableTable(
          Function<? super T, ? extends R> rowFunction,

	return mg.bucketLoader != nil
}

// Describe - implements prometheus.Collector interface.
func (mg *MetricsGroup) Describe(ch chan<- *prometheus.Desc) {
	for _, desc := range mg.Descriptors {
		ch <- desc.toPromDesc(mg.CollectorPath.metricPrefix(), mg.ExtraLabels)
	}
}

// Collect - implements prometheus.Collector interface.
func (mg *MetricsGroup) Collect(ch chan<- prometheus.Metric) {

    checkNonnegative(k, "k");
    checkNotNull(comparator);
    return Collector.of(
        () -> TopKSelector.<T>least(k, comparator),
        TopKSelector::offer,
        TopKSelector::combine,
        TopKSelector::topK,
        Collector.Characteristics.UNORDERED);
  }

  /**
   * Returns a {@code Collector} that returns the {@code k} greatest (relative to the specified

//go:build goexperiment.arenas

/*
The arena package provides the ability to allocate memory for a collection
of Go values and free that space manually all at once, safely. The purpose
of this functionality is to improve efficiency: manually freeing memory
before a garbage collection delays that cycle. Less frequent cycles means
the CPU cost of the garbage collector is incurred less frequently.

import com.google.common.base.Equivalence;
import com.google.common.collect.ImmutableSet.Builder;
import com.google.common.collect.testing.ListTestSuiteBuilder;
import com.google.common.collect.testing.SetTestSuiteBuilder;
import com.google.common.collect.testing.TestStringSetGenerator;
import com.google.common.collect.testing.features.CollectionFeature;
import com.google.common.collect.testing.features.CollectionSize;

    }

    @CanIgnoreReturnValue
    @Override
    public Builder<E> addAll(Iterable<? extends E> elements) {
      if (elements instanceof Collection) {
        Collection<?> collection = (Collection<?>) elements;
        contents.ensureCapacity(contents.size() + collection.size());
      }
      super.addAll(elements);
      return this;
    }

    @CanIgnoreReturnValue
    @Override