import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.Comparator;
import java.util.Iterator;
import java.util.Map;
import java.util.SortedMap;
import java.util.TreeMap;
import java.util.function.BinaryOperator;
import java.util.function.Function;
import java.util.stream.Collector;
import java.util.stream.Collectors;
import org.jspecify.annotations.Nullable;

/**

    buffer[i] = buffer[j];
    buffer[j] = tmp;
  }

  /*
   * While the current implementation returns `this`, that's not something we mean to guarantee.
   * Anyway, the purpose of this method is to implement a BinaryOperator combiner for a Collector,
   * so its return value will get used naturally.
   */
  @SuppressWarnings("CanIgnoreReturnValueSuggester")
  TopKSelector<T> combine(TopKSelector<T> other) {

import java.util.Comparator;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.SortedMap;
import java.util.function.BinaryOperator;
import java.util.function.Function;
import java.util.stream.Collector;
import java.util.stream.Collectors;
import org.jspecify.annotations.Nullable;

/**

import java.util.Map;
import java.util.Set;
import java.util.SortedMap;
import java.util.Spliterator;
import java.util.Spliterators;
import java.util.function.BiFunction;
import java.util.function.BinaryOperator;
import java.util.function.Function;
import java.util.stream.Collector;
import java.util.stream.Collectors;
import org.jspecify.annotations.Nullable;

/**