private TopKSelector(Comparator<? super T> comparator, int k) {
    this.comparator = checkNotNull(comparator, "comparator");
    this.k = k;
    checkArgument(k >= 0, "k (%s) must be >= 0", k);
    checkArgument(k <= Integer.MAX_VALUE / 2, "k (%s) must be <= Integer.MAX_VALUE / 2", k);
    this.buffer = (T[]) new Object[Math.multiplyExact(k, 2)];
    this.bufferSize = 0;
    this.threshold = null;
  }

  /**

import java.util.ConcurrentModificationException;
import java.util.Iterator;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@code clear()} operations on a collection. Can't be invoked
 * directly; please see {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}.
 *
 * @author George van den Driessche
 */
@GwtCompatible

import java.util.Collection;
import java.util.Set;
import org.jspecify.annotations.NullUnmarked;

/**
 * Variant of {@link SerializableTester} that does not require the reserialized object's class to be
 * identical to the original.
 *
 * @author Chris Povirk
 */
/*
 * The whole thing is really @GwtIncompatible, but GwtJUnitConvertedTestModule doesn't have a

import static com.google.common.base.Preconditions.checkArgument;

import java.lang.reflect.Type;
import java.lang.reflect.TypeVariable;
import org.jspecify.annotations.Nullable;

/**
 * Captures a free type variable that can be used in {@link TypeToken#where}. For example:
 *
 * {@snippet :
 * static <T> TypeToken<List<T>> listOf(Class<T> elementType) {
 *   return new TypeToken<List<T>>() {}
 *       .where(new TypeParameter<T>() {}, elementType);

 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 */

 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *

 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *

 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *

     * detail message. The cause is not initialized, and may subsequently be
     * initialized by a call to {@link #initCause}.
     */
    public InterpolatorException() {}

    /**
     * Constructs a new InterpolatorException with the specified detail message.
     * The cause is not initialized, and may subsequently be initialized by
     * a call to {@link #initCause}.
     *

        return null;
      }
      copy(resourceUrl, file);
    }

    return file;
  }

  /**
   * Creates a new temp dir for testing. The returned directory and all contents of it will be
   * deleted in the tear-down for this test.
   */
  protected final File createTempDir() throws IOException {
    File tempFile = File.createTempFile("IoTestCase", "");
    if (!tempFile.delete() || !tempFile.mkdir()) {