### Question:
AccountLocalConfigPermissioningController implements TransactionPermissioningProvider { static boolean isValidAccountString(final String account) { try { if (account == null || !account.startsWith("0x")) { return false; } Bytes bytes = Bytes.fromHexString(account); return bytes.size() == ACCOUNT_BYTES_SIZE; } catch (NullPointerException | IndexOutOfBoundsException | IllegalArgumentException e) { return false; } } AccountLocalConfigPermissioningController(
      final LocalPermissioningConfiguration configuration, final MetricsSystem metricsSystem);  AccountLocalConfigPermissioningController(
      final LocalPermissioningConfiguration configuration,
      final AllowlistPersistor allowlistPersistor,
      final MetricsSystem metricsSystem); AllowlistOperationResult addAccounts(final List<String> accounts); AllowlistOperationResult removeAccounts(final List<String> accounts); boolean contains(final String account); List<String> getAccountAllowlist(); synchronized void reload(); @Override boolean isPermitted(final Transaction transaction);  }### Answer:
@Test public void accountThatDoesNotStartWith0xIsNotValid() { assertThat(AccountLocalConfigPermissioningController.isValidAccountString("bob")).isFalse(); assertThat( AccountLocalConfigPermissioningController.isValidAccountString( "b9b81ee349c3807e46bc71aa2632203c5b462032")) .isFalse(); assertThat( AccountLocalConfigPermissioningController.isValidAccountString( "0xb9b81ee349c3807e46bc71aa2632203c5b462032")) .isTrue(); }