String toTest =
        MoreObjects.toStringHelper(new TestClass())
            .omitNullValues()
            .omitNullValues()
            .add("field1", "Hello")
            .omitNullValues()
            .add("field2", "Googley")
            .omitNullValues()
            .add("field3", "World")
            .toString();

     * methods, is not significant.
     *
     * @since 18.0 (since 12.0 as {@code Objects.ToStringHelper.omitNullValues}).
     */
    @CanIgnoreReturnValue
    public ToStringHelper omitNullValues() {
      omitNullValues = true;
      return this;
    }

    /**
     * Configures the {@link ToStringHelper} so {@link #toString()} will ignore properties with

     * methods, is not significant.
     *
     * @since 18.0 (since 12.0 as {@code Objects.ToStringHelper.omitNullValues}).
     */
    @CanIgnoreReturnValue
    public ToStringHelper omitNullValues() {
      omitNullValues = true;
      return this;
    }

    /**
     * Configures the {@link ToStringHelper} so {@link #toString()} will ignore properties with