public ToStringHelper addValue(@Nullable Object value) {
      return addHolder(value);
    }

    /**
     * Adds an unnamed value to the formatted output.
     *
     * <p>It is strongly encouraged to use {@link #add(String, boolean)} instead and give value a
     * readable name.
     *
     * @since 18.0 (since 11.0 as {@code Objects.ToStringHelper.addValue}).
     */
    @CanIgnoreReturnValue

  public void testToString_addValueWithNullValue() {
    String result =
        MoreObjects.toStringHelper(new TestClass())
            .addValue(null)
            .addValue("Hello")
            .addValue(null)
            .toString();
    String expected = "TestClass{null, Hello, null}";

    assertThat(result).isEqualTo(expected);
  }

    public ToStringHelper addValue(@Nullable Object value) {
      return addHolder(value);
    }

    /**
     * Adds an unnamed value to the formatted output.
     *
     * <p>It is strongly encouraged to use {@link #add(String, boolean)} instead and give value a
     * readable name.
     *
     * @since 18.0 (since 11.0 as {@code Objects.ToStringHelper.addValue}).
     */
    @CanIgnoreReturnValue

   * Returns a string representation for this CacheBuilderSpec instance. The form of this
   * representation is not guaranteed.
   */
  @Override
  public String toString() {
    return MoreObjects.toStringHelper(this).addValue(toParsableString()).toString();
  }

  @Override
  public int hashCode() {
    return Objects.hash(
        initialCapacity,
        maximumSize,
        maximumWeight,
        concurrencyLevel,

   * Returns a string representation for this CacheBuilderSpec instance. The form of this
   * representation is not guaranteed.
   */
  @Override
  public String toString() {
    return MoreObjects.toStringHelper(this).addValue(toParsableString()).toString();
  }

  @Override
  public int hashCode() {
    return Objects.hash(
        initialCapacity,
        maximumSize,
        maximumWeight,
        concurrencyLevel,

        callback.onFailure(e);
        return;
      }
      callback.onSuccess(value);
    }

    @Override
    public String toString() {
      return MoreObjects.toStringHelper(this).addValue(callback).toString();
    }
  }

  /**
   * Returns the result of the input {@code Future}, which must have already completed.
   *

    }
    if (valueStrength != null) {
      s.add("valueStrength", Ascii.toLowerCase(valueStrength.toString()));
    }
    if (keyEquivalence != null) {
      s.addValue("keyEquivalence");
    }
    return s.toString();
  }

      s.add("valueStrength", Ascii.toLowerCase(valueStrength.toString()));
    }
    if (keyEquivalence != null) {
      s.addValue("keyEquivalence");
    }
    if (valueEquivalence != null) {
      s.addValue("valueEquivalence");
    }
    if (removalListener != null) {
      s.addValue("removalListener");
    }
    return s.toString();
  }

  /**

    }
    if (valueStrength != null) {
      s.add("valueStrength", Ascii.toLowerCase(valueStrength.toString()));
    }
    if (keyEquivalence != null) {
      s.addValue("keyEquivalence");
    }
    return s.toString();
  }

      s.add("valueStrength", Ascii.toLowerCase(valueStrength.toString()));
    }
    if (keyEquivalence != null) {
      s.addValue("keyEquivalence");
    }
    if (valueEquivalence != null) {
      s.addValue("valueEquivalence");
    }
    if (removalListener != null) {
      s.addValue("removalListener");
    }
    return s.toString();
  }

  /**