return (ImmutableSortedMap<K, V>) NATURAL_EMPTY_MAP;
  }

  /** Returns an immutable map containing a single entry. */
  public static <K extends Comparable<? super K>, V> ImmutableSortedMap<K, V> of(K k1, V v1) {
    return of(Ordering.natural(), k1, v1);
  }

  /** Returns an immutable map containing a single entry. */

    return (ImmutableBiMap<K, V>) RegularImmutableBiMap.EMPTY;
  }

  /** Returns an immutable bimap containing a single entry. */
  public static <K, V> ImmutableBiMap<K, V> of(K k1, V v1) {
    checkEntryNotNull(k1, v1);
    return new RegularImmutableBiMap<>(new Object[] {k1, v1}, 1);
  }

  /**
   * Returns an immutable map containing the given entries, in order.
   *

import com.google.common.annotations.J2ktIncompatible;
import com.google.errorprone.annotations.Immutable;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Map.Entry;

/** A {@code RegularImmutableTable} optimized for sparse data. */
@GwtCompatible
@Immutable(containerOf = {"R", "C", "V"})
final class SparseImmutableTable<R, C, V> extends RegularImmutableTable<R, C, V> {

import org.apache.maven.api.annotations.Immutable;
import org.apache.maven.api.annotations.Nonnull;
import org.apache.maven.api.annotations.NotThreadSafe;
import org.apache.maven.api.annotations.Nullable;

import static java.util.Objects.requireNonNull;

/**
 * A request for installing one or more artifacts in the local repository.
 *
 * @since 4.0.0
 */
@Experimental
@Immutable

  }

  /**
   * Returns an empty immutable table.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  @SuppressWarnings("unchecked")
  public static <R, C, V> ImmutableTable<R, C, V> of() {
    return (ImmutableTable<R, C, V>) SparseImmutableTable.EMPTY;
  }

  /** Returns an immutable table containing a single cell. */

    return (ImmutableBiMap<K, V>) RegularImmutableBiMap.EMPTY;
  }

  /** Returns an immutable bimap containing a single entry. */
  public static <K, V> ImmutableBiMap<K, V> of(K k1, V v1) {
    return new SingletonImmutableBiMap<>(k1, v1);
  }

  /**
   * Returns an immutable map containing the given entries, in order.
   *
   * @throws IllegalArgumentException if duplicate keys or values are added

    return new SingletonImmutableList<>(e1);
  }

  /**
   * Returns an immutable list containing the given elements, in order.
   *
   * @throws NullPointerException if any element is null
   */
  public static <E> ImmutableList<E> of(E e1, E e2) {
    return construct(e1, e2);
  }

  /**
   * Returns an immutable list containing the given elements, in order.
   *

import com.google.errorprone.annotations.Immutable;
import com.google.errorprone.annotations.InlineMe;

/**
 * A {@link ValueGraph} whose elements and structural relationships will never change. Instances of
 * this class may be obtained with {@link #copyOf(ValueGraph)}.
 *
 * <p>See the Guava User's Guide's <a
 * href="https://github.com/google/guava/wiki/GraphsExplained#immutable-implementations">discussion

/** Returns an immutable wrap of this. */
@Suppress("NOTHING_TO_INLINE")
internal inline fun <T> List<T>.unmodifiable(): List<T> = Collections.unmodifiableList(this)

/** Returns an immutable wrap of this. */
@Suppress("NOTHING_TO_INLINE")
internal inline fun <T> Set<T>.unmodifiable(): Set<T> = Collections.unmodifiableSet(this)

/** Returns an immutable wrap of this. */
@Suppress("NOTHING_TO_INLINE")

    if (actualIterator.hasNext()) {
      fail("index " + i + ", expected is exhausted, actual <" + actualIterator.next() + ">");
    }
  }

  /**
   * Verifies that a collection is immutable.
   *
   * <p>A collection is considered immutable if:
   *
   * <ol>
   *   <li>All its mutation methods result in UnsupportedOperationException, and do not change the
   *       underlying contents.