if (ownerType == null) {
      return newParameterizedType(rawType, arguments);
    }
    // ParameterizedTypeImpl constructor already checks, but we want to throw NPE before IAE
    checkNotNull(arguments);
    checkArgument(rawType.getEnclosingClass() != null, "Owner type for unenclosed %s", rawType);
    return new ParameterizedTypeImpl(ownerType, rawType, arguments);
  }

    }
  }

  public void testTryParse_withNullGwt() {
    assertThat(Longs.tryParse("null")).isNull();
    try {
      Longs.tryParse(null);
      fail("Expected NPE");
    } catch (NullPointerException expected) {
    }
  }

  }

  @GwtIncompatible
  public void testTryParse_withNullNoGwt() {
    assertThat(Floats.tryParse("null")).isNull();
    try {
      Floats.tryParse(null);
      fail("Expected NPE");
    } catch (NullPointerException expected) {
    }
  }

    }
  }

  public void testTryParse_withNullGwt() {
    assertThat(Ints.tryParse("null")).isNull();
    try {
      Ints.tryParse(null);
      fail("Expected NPE");
    } catch (NullPointerException expected) {
    }
  }

  }

  @GwtIncompatible
  public void testTryParse_withNullNoGwt() {
    assertThat(Doubles.tryParse("null")).isNull();
    try {
      Doubles.tryParse(null);
      fail("Expected NPE");
    } catch (NullPointerException expected) {
    }
  }

  }

  @GwtIncompatible
  public void testTryParse_withNullNoGwt() {
    assertThat(Floats.tryParse("null")).isNull();
    try {
      Floats.tryParse(null);
      fail("Expected NPE");
    } catch (NullPointerException expected) {
    }
  }

    }
  }

  public void testTryParse_withNullGwt() {
    assertThat(Longs.tryParse("null")).isNull();
    try {
      Longs.tryParse(null);
      fail("Expected NPE");
    } catch (NullPointerException expected) {
    }
  }

  }

  @GwtIncompatible
  public void testTryParse_withNullNoGwt() {
    assertThat(Doubles.tryParse("null")).isNull();
    try {
      Doubles.tryParse(null);
      fail("Expected NPE");
    } catch (NullPointerException expected) {
    }
  }

    }
  }

  public void testTryParse_withNullGwt() {
    assertThat(Ints.tryParse("null")).isNull();
    try {
      Ints.tryParse(null);
      fail("Expected NPE");
    } catch (NullPointerException expected) {
    }
  }

   * nulls as long as the *last* element is *not* null.
   *
   * (To "go out of its way," the method tracks a `set` bit so that it can distinguish "the final
   * split has a last element of null, so throw NPE" from "the final split was empty, so look for an
   * element in the prior one.")
   */
  public static <T> java.util.Optional<T> findLast(Stream<T> stream) {
    class OptionalState {
      boolean set = false;