*/
    runConcurrentlyMutatedTest(elements(), ops(add(1), add(2)), wrap);

    runConcurrentlyMutatedTest(elements(), ops(add(1), nop()), wrap);

    runConcurrentlyMutatedTest(elements(), ops(add(1), remove()), wrap);

    runConcurrentlyMutatedTest(elements(), ops(nop(), add(1)), wrap);

    runConcurrentlyMutatedTest(elements(1), ops(remove(), nop()), wrap);

    runConcurrentlyMutatedTest(elements(1), ops(remove(), add(2)), wrap);

     */
    runConcurrentlyMutatedTest(elements(), ops(add(1), add(2)), wrap);

    runConcurrentlyMutatedTest(elements(), ops(add(1), nop()), wrap);

    runConcurrentlyMutatedTest(elements(), ops(add(1), remove()), wrap);

    runConcurrentlyMutatedTest(elements(), ops(nop(), add(1)), wrap);

    runConcurrentlyMutatedTest(elements(1), ops(remove(), nop()), wrap);

    runConcurrentlyMutatedTest(elements(1), ops(remove(), add(2)), wrap);

        .addEqualityGroup(
            LENGTH_EQUIVALENCE.wrap("hello"),
            LENGTH_EQUIVALENCE.wrap("hello"),
            LENGTH_EQUIVALENCE.wrap("world"))
        .addEqualityGroup(LENGTH_EQUIVALENCE.wrap("hi"), LENGTH_EQUIVALENCE.wrap("yo"))
        .addEqualityGroup(
            LENGTH_EQUIVALENCE.<@Nullable String>wrap(null),
            LENGTH_EQUIVALENCE.<@Nullable String>wrap(null))

                return wrap((Multimap<?, ?>) delegate);
              }
            });
  }

  public void testEquals() {
    Multimap<Integer, String> map1 = ImmutableMultimap.of(1, "one");
    Multimap<Integer, String> map2 = ImmutableMultimap.of(2, "two");
    new EqualsTester()
        .addEqualityGroup(map1, wrap(map1), wrap(map1))
        .addEqualityGroup(map2, wrap(map2))
        .testEquals();
  }

                return wrap((SetMultimap<?, ?>) delegate);
              }
            });
  }

  public void testEquals() {
    SetMultimap<Integer, String> map1 = ImmutableSetMultimap.of(1, "one");
    SetMultimap<Integer, String> map2 = ImmutableSetMultimap.of(2, "two");
    new EqualsTester()
        .addEqualityGroup(map1, wrap(map1), wrap(map1))
        .addEqualityGroup(map2, wrap(map2))

                return wrap((SetMultimap<?, ?>) delegate);
              }
            });
  }

  public void testEquals() {
    SetMultimap<Integer, String> map1 = ImmutableSetMultimap.of(1, "one");
    SetMultimap<Integer, String> map2 = ImmutableSetMultimap.of(2, "two");
    new EqualsTester()
        .addEqualityGroup(map1, wrap(map1), wrap(map1))
        .addEqualityGroup(map2, wrap(map2))

        .addEqualityGroup(
            LENGTH_EQUIVALENCE.wrap("hello"),
            LENGTH_EQUIVALENCE.wrap("hello"),
            LENGTH_EQUIVALENCE.wrap("world"))
        .addEqualityGroup(LENGTH_EQUIVALENCE.wrap("hi"), LENGTH_EQUIVALENCE.wrap("yo"))
        .addEqualityGroup(
            LENGTH_EQUIVALENCE.<@Nullable String>wrap(null),
            LENGTH_EQUIVALENCE.<@Nullable String>wrap(null))

            }
            return copyInternal((FileInputStream) in, wrap(out));
        }
        if (out instanceof FileOutputStream) {
            return copyInternal(wrap(in), (FileOutputStream) out);
        }
        return copyInternal(wrap(in), wrap(out));
    }

    // ////////////////////////////////////////////////////////////////
    // from InputStream to Writer

  }

  /**
   * Wraps an object so that {@link #equals(Object)} and {@link #hashCode()} delegate to an {@link
   * Equivalence}.
   *
   * <p>For example, given an {@link Equivalence} for {@link String strings} named {@code equiv}
   * that tests equivalence using their lengths:
   *
   * <pre>{@code
   * equiv.wrap("a").equals(equiv.wrap("b")) // true
   * equiv.wrap("a").equals(equiv.wrap("hello")) // false
   * }</pre>

  }

  /**
   * Wraps an object so that {@link #equals(Object)} and {@link #hashCode()} delegate to an {@link
   * Equivalence}.
   *
   * <p>For example, given an {@link Equivalence} for {@link String strings} named {@code equiv}
   * that tests equivalence using their lengths:
   *
   * <pre>{@code
   * equiv.wrap("a").equals(equiv.wrap("b")) // true
   * equiv.wrap("a").equals(equiv.wrap("hello")) // false
   * }</pre>