### Question:
OpLoadConfiguration implements CheckstyleCommand<HasCsConfig> { @Override public HasCsConfig execute(@NotNull final Project currentProject) throws CheckstyleException { try (InputStream is = rulesContainer.inputStream(checkstyleClassLoader())) { Configuration configuration = callLoadConfiguration(is); if (configuration == null) { throw new CheckstyleException("Couldn't find root module in " + rulesContainer.filePath()); } resolveFilePaths(currentProject, configuration); return new CsConfigObject(configuration); } catch (IOException e) { throw new CheckstyleException("Error loading file", e); } } OpLoadConfiguration(@NotNull final ConfigurationLocation configurationLocation,
                               @NotNull final CheckstyleProjectService checkstyleProjectService);  OpLoadConfiguration(@NotNull final ConfigurationLocation configurationLocation,
                               final Map<String, String> properties,
                               @NotNull final CheckstyleProjectService checkstyleProjectService);  OpLoadConfiguration(final ConfigurationLocation configurationLocation,
                               final Map<String, String> properties,
                               final Module module,
                               @NotNull final CheckstyleProjectService checkstyleProjectService);  OpLoadConfiguration(@NotNull final VirtualFile rulesFile,
                               @NotNull final CheckstyleProjectService checkstyleProjectService);  OpLoadConfiguration(@NotNull final VirtualFile rulesFile,
                               final Map<String, String> properties,
                               @NotNull final CheckstyleProjectService checkstyleProjectService);  OpLoadConfiguration(@NotNull final String fileContent,
                               @NotNull final CheckstyleProjectService checkstyleProjectService); private  OpLoadConfiguration(final RulesContainer rulesContainer,
                                final Map<String, String> properties,
                                final Module module,
                                final CheckstyleProjectService checkstyleProjectService); @Override HasCsConfig execute(@NotNull final Project currentProject);  }### Answer:
@Test public void testNoConfiguration() { OpLoadConfiguration testee = new OpLoadConfiguration(configurationLocation, null, module, mock(CheckstyleProjectService.class)) { @Override Configuration callLoadConfiguration(final InputStream inputStream) { return null; } }; try { testee.execute(PROJECT); } catch (CheckstyleException e) { assertTrue(e.getMessage().contains("Couldn't find root module")); } }