### Question:
JibSystemProperties { public static void checkHttpTimeoutProperty() throws NumberFormatException { checkNumericSystemProperty(HTTP_TIMEOUT, Range.atLeast(0)); } private  JibSystemProperties(); static int getHttpTimeout(); static boolean useCrossRepositoryBlobMounts(); static boolean serializeExecution(); static boolean sendCredentialsOverHttp(); static boolean isUserAgentEnabled(); static void checkHttpTimeoutProperty(); static void checkProxyPortProperty(); static boolean skipExistingImages(); static final String UPSTREAM_CLIENT; @VisibleForTesting static final String HTTP_TIMEOUT; @VisibleForTesting
  static final String SEND_CREDENTIALS_OVER_HTTP; @VisibleForTesting static final String SKIP_EXISTING_IMAGES; }### Answer:
@Test public void testCheckHttpTimeoutProperty_okWhenUndefined() throws NumberFormatException { System.clearProperty(JibSystemProperties.HTTP_TIMEOUT); JibSystemProperties.checkHttpTimeoutProperty(); }
@Test public void testCheckHttpTimeoutProperty_stringValue() { System.setProperty(JibSystemProperties.HTTP_TIMEOUT, "random string"); try { JibSystemProperties.checkHttpTimeoutProperty(); Assert.fail(); } catch (NumberFormatException ex) { Assert.assertEquals("jib.httpTimeout must be an integer: random string", ex.getMessage()); } }