assertEquals("{a=[a1, a4, a4], b=[b6]}", transformed.toString());
  }

  @J2ktIncompatible // Synchronized
  public void testSynchronizedMultimapSampleCodeCompilation() {
    // Extra indirection for J2KT, to avoid error: not enough information to infer type variable K
    this.<@Nullable Object, @Nullable Object>genericTestSynchronizedMultimapSampleCodeCompilation();
  }

  @J2ktIncompatible // Synchronized

         * be used with collections that may contain null. This collection never contains nulls, so
         * we could return `Object[]`. But this class is private and J2KT cannot change return types
         * in overrides, so we declare `@Nullable Object[]` as the return type.
         */
        return ObjectArrays.toArrayImpl(delegate());
      }
    }

    @Override

         * be used with collections that may contain null. This collection never contains nulls, so
         * we could return `Object[]`. But this class is private and J2KT cannot change return types
         * in overrides, so we declare `@Nullable Object[]` as the return type.
         */
        return ObjectArrays.toArrayImpl(delegate());
      }
    }

    @Override

       * be used with collections that may contain null. This collection never contains nulls, so we
       * could return `Object[]`. But this class is private and J2KT cannot change return types in
       * overrides, so we declare `@Nullable Object[]` as the return type.
       */
      return standardToArray();
    }

    @Override

       * be used with collections that may contain null. This collection never contains nulls, so we
       * could return `Object[]`. But this class is private and J2KT cannot change return types in
       * overrides, so we declare `@Nullable Object[]` as the return type.
       */
      return standardToArray();
    }

    @Override