### Question:
AllowlistPersistor { @VisibleForTesting void removeExistingConfigItem(final ALLOWLIST_TYPE allowlistType) throws IOException { List<String> otherConfigItems = existingConfigItems(configurationFile.toPath()) .entrySet() .parallelStream() .filter(listType -> !listType.getKey().equals(allowlistType)) .map(keyVal -> valueListToTomlArray(keyVal.getKey(), keyVal.getValue())) .collect(Collectors.toList()); Files.write( configurationFile.toPath(), otherConfigItems, StandardOpenOption.WRITE, StandardOpenOption.TRUNCATE_EXISTING); } AllowlistPersistor(final String configurationFile); static boolean verifyConfigFileMatchesState(
      final ALLOWLIST_TYPE allowlistType,
      final Collection<String> checkLists,
      final Path configurationFilePath); boolean verifyConfigFileMatchesState(
      final ALLOWLIST_TYPE allowlistType, final Collection<String> checkLists); synchronized void updateConfig(
      final ALLOWLIST_TYPE allowlistType, final Collection<String> updatedAllowlistValues); @VisibleForTesting static void addNewConfigItem(
      final ALLOWLIST_TYPE allowlistType,
      final Collection<String> allowlistValues,
      final Path configFilePath);  }### Answer:
@Test public void lineShouldBeRemoved() throws IOException { ALLOWLIST_TYPE keyForRemoval = ALLOWLIST_TYPE.ACCOUNTS; assertThat(countLines()).isEqualTo(2); assertThat(hasKey(keyForRemoval)).isTrue(); allowlistPersistor.removeExistingConfigItem(keyForRemoval); assertThat(countLines()).isEqualTo(1); assertThat(hasKey(keyForRemoval)).isFalse(); }