UnsignedLong unsignedValue = UnsignedLong.fromLongBits(value);
      assertWithMessage("Double value of %s", unsignedValue)
          .that(unsignedValue.doubleValue())
          .isEqualTo(unsignedValue.bigIntegerValue().doubleValue());
    }
  }

  public void testPlus() {
    for (long a : TEST_LONGS) {
      for (long b : TEST_LONGS) {
        UnsignedLong aUnsigned = UnsignedLong.fromLongBits(a);

      UnsignedLong unsignedValue = UnsignedLong.fromLongBits(value);
      assertWithMessage("Double value of %s", unsignedValue)
          .that(unsignedValue.doubleValue())
          .isEqualTo(unsignedValue.bigIntegerValue().doubleValue());
    }
  }

  public void testPlus() {
    for (long a : TEST_LONGS) {
      for (long b : TEST_LONGS) {
        UnsignedLong aUnsigned = UnsignedLong.fromLongBits(a);

        } else if (value instanceof Long || value instanceof Integer) {
            buf.append(((Number) value).longValue());
        } else if (value instanceof Number) {
            buf.append(((Number) value).doubleValue());
        } else {
            buf.append('"').append(StringEscapeUtils.escapeJson(value.toString())).append('"');
        }
        return buf;
    }

    /**

        new EntryTransformer<Number, Number, Double>() {
          @Override
          public Double transformEntry(Number key, Number value) {
            return key.doubleValue() + value.doubleValue();
          }
        };

    Map<Object, Double> objectKeyed;
    Map<Number, Double> numberKeyed;
    Map<Integer, Double> integerKeyed;

        new EntryTransformer<Number, Number, Double>() {
          @Override
          public Double transformEntry(Number key, Number value) {
            return key.doubleValue() + value.doubleValue();
          }
        };

    Map<Object, Double> objectKeyed;
    Map<Number, Double> numberKeyed;
    Map<Integer, Double> integerKeyed;

                }
            } else if (doubleFieldSet.contains(key)) {
                if (value instanceof final Number num) {
                    value = num.doubleValue();
                } else {
                    value = DfTypeUtil.toDouble(value.toString());
                }
            }
            return new Pair<>(key, value);