* <p>If multiple input elements map to the same row and column, the specified merging function is
   * used to combine the values. Like {@link
   * java.util.stream.Collectors#toMap(java.util.function.Function, java.util.function.Function,
   * BinaryOperator, java.util.function.Supplier)}, this Collector throws a {@code
   * NullPointerException} on null values returned from {@code valueFunction}, and treats nulls

      Collector<T, ?, ImmutableSortedMap<K, V>> toImmutableSortedMap(
          Function<? super T, ? extends K> keyFunction,
          Function<? super T, ? extends V> valueFunction) {
    return CollectCollectors.toImmutableSortedMap(Ordering.natural(), keyFunction, valueFunction);
  }

  public static <T extends @Nullable Object, K, V>
      Collector<T, ?, ImmutableSortedMap<K, V>> toImmutableSortedMap(

   */
  public static <T extends @Nullable Object, K, V>
      Collector<T, ?, ImmutableListMultimap<K, V>> toImmutableListMultimap(
          Function<? super T, ? extends K> keyFunction,
          Function<? super T, ? extends V> valueFunction) {
    return CollectCollectors.toImmutableListMultimap(keyFunction, valueFunction);
  }

  /**
   * Returns a {@code Collector} accumulating entries into an {@code ImmutableListMultimap}. Each

            final ByteArrayOutputStream collector = new ByteArrayOutputStream();
            final ASN1OutputStream der = ASN1OutputStream.create(collector, ASN1Encoding.DER);
            final DERTaggedObject derApplicationSpecific = new DERTaggedObject(false, BERTags.APPLICATION, 0, new DERSequence(ev));
            der.writeObject(derApplicationSpecific);
            return collector.toByteArray();
        } catch (final IOException ex) {

   * operation is performed. (This differs from the {@code Collector} returned by {@link
   * Collectors#toMap(Function, Function)}, which throws an {@code IllegalStateException}.)
   *
   * @since 21.0
   */
  public static <T extends @Nullable Object, K, V>
      Collector<T, ?, ImmutableBiMap<K, V>> toImmutableBiMap(
          Function<? super T, ? extends K> keyFunction,

  public static <T extends @Nullable Object, K, V>
      Collector<T, ?, ImmutableListMultimap<K, V>> toImmutableListMultimap(
          Function<? super T, ? extends K> keyFunction,
          Function<? super T, ? extends V> valueFunction) {
    return CollectCollectors.toImmutableListMultimap(keyFunction, valueFunction);
  }

  /**
   * Returns a {@code Collector} accumulating entries into an {@code ImmutableListMultimap}. Each

import java.lang.ref.SoftReference;
import org.jspecify.annotations.Nullable;

/**
 * Soft reference with a {@code finalizeReferent()} method which a background thread invokes after
 * the garbage collector reclaims the referent. This is a simpler alternative to using a {@link
 * ReferenceQueue}.
 *
 * @author Bob Lee
 * @since 2.0
 */
@J2ktIncompatible
@GwtIncompatible

import java.lang.ref.SoftReference;
import org.jspecify.annotations.Nullable;

/**
 * Soft reference with a {@code finalizeReferent()} method which a background thread invokes after
 * the garbage collector reclaims the referent. This is a simpler alternative to using a {@link
 * ReferenceQueue}.
 *
 * @author Bob Lee
 * @since 2.0
 */
@J2ktIncompatible
@GwtIncompatible

import java.lang.ref.ReferenceQueue;
import org.jspecify.annotations.Nullable;

/**
 * Phantom reference with a {@code finalizeReferent()} method which a background thread invokes
 * after the garbage collector reclaims the referent. This is a simpler alternative to using a
 * {@link ReferenceQueue}.
 *
 * <p>Unlike a normal phantom reference, this reference will be cleared automatically.
 *
 * @author Bob Lee
 * @since 2.0

 * @since 4.0.0
 */
@Experimental
public interface ModelTransformer {

    /**
     * Apply a transformation on the file model.
     *
     * @param model the input model
     * @param problems the problem collector to report any issues encountered during transformation
     * @return the transformed model, or the input model if no transformation is needed
     */
    @Nonnull
    Model transform(