@Test
  public void parsedNumberSerializeDeserialize_returnsBigDecimal() throws Exception {
    JsonElement numElement = JsonParser.parse("42");
    Number num = numElement.getAsNumber();
    ByteArrayOutputStream bytes = new ByteArrayOutputStream();
    ObjectOutputStream out = new ObjectOutputStream(bytes);
    assertThrows(NotSerializableException.class, () -> out.writeObject(num));
  }
Tests for Tink's internal {@link JsonParser}.
java_src/src/test/java/com/google/crypto/tink/internal/JsonParserTest.java