LogStream.setInstance(stream1);
        LogStream instance1 = LogStream.getInstance();

        LogStream.setInstance(stream2);
        LogStream instance2 = LogStream.getInstance();

        // Each setInstance should create a new LogStream
        assertNotNull(instance1);
        assertNotNull(instance2);
        // The second setInstance replaces the first, so they should not be the same

        LogStream.level = level;
    }

    /**
     * This must be called before <code>getInstance</code> is called or
     * it will have no effect.
     *
     * @param stream the PrintStream to use for logging
     */
    public static void setInstance(final PrintStream stream) {
        inst = new LogStream(stream);
    }

    /**
     * Returns the singleton LogStream instance.

     * @throws RuntimeException
     *             If a {@link NoSuchAlgorithmException} occurs
     */
    public static MessageDigest getInstance(final String algorithm) {
        assertArgumentNotEmpty("algorithm", algorithm);

        try {
            return MessageDigest.getInstance(algorithm);
        } catch (final NoSuchAlgorithmException e) {
            throw new NoSuchAlgorithmRuntimeException(e);
        }
    }

    in.put(Double.class, Math.PI);
    ClassToInstanceMap<Number> map = ImmutableClassToInstanceMap.copyOf(in);
    assertEquals(2, map.size());

    Number zero = map.getInstance(Number.class);
    assertEquals(0, zero);

    Double pi = map.getInstance(Double.class);
    assertThat(pi).isEqualTo(Math.PI);

    assertSame(map, ImmutableClassToInstanceMap.copyOf(map));
  }

  public void testCopyOf_map_nulls() {

            final ASN1Sequence sequence = ASN1Sequence.getInstance(tagged, true);
            final Enumeration<?> fields = sequence.getObjects();
            while (fields.hasMoreElements()) {
                tagged = (ASN1TaggedObject) fields.nextElement();
                switch (tagged.getTagNo()) {
                case 0:
                    final ASN1Enumerated enumerated = ASN1Enumerated.getInstance(tagged, true);

        assertNotNull(TimeoutManager.getInstance().thread);
        Thread.sleep(2000);
        assertEquals(count, expiredCount);
        assertEquals(1, TimeoutManager.getInstance().getTimeoutTaskCount());
        task.cancel();
        Thread.sleep(2000);
        assertEquals(0, TimeoutManager.getInstance().getTimeoutTaskCount());
        assertNull(TimeoutManager.getInstance().thread);
    }

		var rowsAffected int64
		tx = db.getInstance()

		// the reflection length judgment of the optimized value
		reflectLen := reflectValue.Len()

		callFc := func(tx *DB) error {
			for i := 0; i < reflectLen; i += batchSize {
				ends := i + batchSize
				if ends > reflectLen {
					ends = reflectLen
				}

				subtx := tx.getInstance()
				subtx.Statement.Dest = reflectValue.Slice(i, ends).Interface()

            ASN1Sequence sequence = ASN1Sequence.getInstance(tagged, true);
            final Enumeration<ASN1Object> fields = sequence.getObjects();
            while (fields.hasMoreElements()) {
                tagged = (ASN1TaggedObject) fields.nextElement();
                switch (tagged.getTagNo()) {
                case 0:
                    sequence = ASN1Sequence.getInstance(tagged, true);

        byte[] data = "Hi There".getBytes();

        // Calculate expected HMACT64 result manually
        MessageDigest md5 = MessageDigest.getInstance("MD5");
        byte[] ipad = new byte[64];
        byte[] opad = new byte[64];

        // HMACT64 specific: truncate key to 64 bytes if needed
        int keyLen = Math.min(key.length, 64);

            Certificate certificate = CertificateFactory.getInstance("X.509").generateCertificate(in);

            KeyStore keyStore = KeyStore.getInstance(KeyStore.getDefaultType());
            keyStore.load(null, null);
            keyStore.setCertificateEntry("server", certificate);

            TrustManagerFactory trustManagerFactory = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());