public OptPane getOptionPane(@NotNull PsiMethod method) {
      return pane(
        string("contract", JavaBundle.message("label.contract"),
               StringValidator.of("java.method.contract", string -> getContractErrorMessage(string, method)))
          .description(HtmlChunk.raw(JavaBundle.message("edit.contract.dialog.hint"))),
        checkbox("impure", JavaBundle.message("edit.contract.dialog.checkbox.impure.method"),
                 string("mutates", JavaBundle.message("label.mutates"),
                        StringValidator.of("java.method.mutates", string -> getMutatesErrorMessage(string, method)))
                   .description(HtmlChunk.raw(JavaBundle.message("edit.contract.dialog.mutates.hint")))
        ));
    }
public OptPane getOptionPane(@NotNull PsiMethod method)