* according to the value ordering.
 *
 * <p>The multimap does not store duplicate key-value pairs. Adding a new key-value pair equal to an
 * existing key-value pair has no effect.
 *
 * <p>Null keys and values are permitted (provided, of course, that the respective comparators
 * support them). All optional multimap methods are supported, and all returned views are
 * modifiable.
 *

 * behavior:
 *
 * <pre>{@code
 * BaseEncoding.base16().lowerCase().decode("deadbeef");
 * }</pre>
 *
 * <p>Warning: BaseEncoding instances are immutable. Invoking a configuration method has no effect
 * on the receiving instance; you must store and use the new encoding instance it returns, instead.
 *
 * <pre>{@code
 * // Do NOT do this
 * BaseEncoding hex = BaseEncoding.base16();
 * hex.lowerCase(); // does nothing!

    }

    /**
     * Adds {@code element} to the {@code ImmutableSortedSet}. If the {@code ImmutableSortedSet}
     * already contains {@code element}, then {@code add} has no effect. (only the previously added
     * element is retained).
     *
     * @param element the element to add
     * @return this {@code Builder} object
     * @throws NullPointerException if {@code element} is null

    }

    /**
     * Adds {@code element} to the {@code ImmutableSet}. If the {@code ImmutableSet} already
     * contains {@code element}, then {@code add} has no effect (only the previously added element
     * is retained).
     *
     * @param element the element to add
     * @return this {@code Builder} object
     * @throws NullPointerException if {@code element} is null

      n = unique;
    }

    /**
     * Adds {@code element} to the {@code ImmutableSortedSet}. If the {@code ImmutableSortedSet}
     * already contains {@code element}, then {@code add} has no effect. (only the previously added
     * element is retained).
     *
     * @param element the element to add
     * @return this {@code Builder} object
     * @throws NullPointerException if {@code element} is null

public final class Collections2 {
  private Collections2() {}

  /**
   * Returns the elements of {@code unfiltered} that satisfy a predicate. The returned collection is
   * a live view of {@code unfiltered}; changes to one affect the other.
   *
   * <p>The resulting collection's iterator does not support {@code remove()}, but all other
   * collection methods are supported. When given an element that doesn't satisfy the predicate, the

          return oldValue;
        }
        // value changed
      }
    }
  }

  /**
   * Copies all of the mappings from the specified map to this map. The effect of this call is
   * equivalent to that of calling {@code put(k, v)} on this map once for each mapping from key
   * {@code k} to value {@code v} in the specified map. The behavior of this operation is undefined

   * compared. This comparator imposes a "partial ordering" over the type {@code T}. Subsequent
   * changes to the {@code valuesInOrder} list will have no effect on the returned comparator. Null
   * values in the list are not supported.
   *
   * <p>The returned comparator throws a {@link ClassCastException} when it receives an input

 * detailed at {@link ImmutableCollection}.
 *
 * <p><b>Warning:</b> As in all {@link SetMultimap}s, do not modify either a key <i>or a value</i>
 * of a {@code ImmutableSetMultimap} in a way that affects its {@link Object#equals} behavior.
 * Undefined behavior and bugs will result.
 *
 * <p>See the Guava User Guide article on <a href=

  }

  /**
   * Returns a view of the elements of {@code unfiltered} that satisfy a predicate. The returned
   * multiset is a live view of {@code unfiltered}; changes to one affect the other.
   *
   * <p>The resulting multiset's iterators, and those of its {@code entrySet()} and {@code
   * elementSet()}, do not support {@code remove()}. However, all other multiset methods supported