ClassNameCheck implements EslintBasedCheck { @Override public List<Object> configurations() { return Collections.singletonList(new FormatRuleProperty(format)); }  @Override List<Object> configurations(); @Override String eslintKey(); @RuleProperty(
      key = "format",
      description = "Regular expression used to check the class names against.",
      defaultValue = "" + DEFAULT_FORMAT)
  public String format; }
@Test public void configurations() { ClassNameCheck check = new ClassNameCheck(); String defaultConfigAsString = new Gson().toJson(check.configurations()); assertThat(defaultConfigAsString).isEqualTo("[{\"format\":\"^[A-Z][a-zA-Z0-9]*$\"}]"); check.format = "^[_A-Z][a-zA-Z0-9]*$"; String customConfigAsString = new Gson().toJson(check.configurations()); assertThat(customConfigAsString).isEqualTo("[{\"format\":\"^[_A-Z][a-zA-Z0-9]*$\"}]"); }