public static UpdateRequirement fromJson(String json) {
    return JsonUtil.parse(json, UpdateRequirementParser::fromJson);
  }
@Test
  public void testAssertLastAssignedFieldIdFromJson() {
    String requirementType = UpdateRequirementParser.ASSERT_LAST_ASSIGNED_FIELD_ID;
    int lastAssignedFieldId = 12;
    String json =
        String.format(
            "{\"type\":\"%s\",\"last-assigned-field-id\":%d}",
            requirementType, lastAssignedFieldId);
    UpdateRequirement expected =
        new UpdateRequirement.AssertLastAssignedFieldId(lastAssignedFieldId);
    assertEquals(requirementType, expected, UpdateRequirementParser.fromJson(json));
  }