### Concurrency and Burgers { #concurrency-and-burgers }

This idea of **asynchronous** code described above is also sometimes called **"concurrency"**. It is different from **"parallelism"**.

**Concurrency** and **parallelism** both relate to "different things happening more or less at the same time".

        byte[] encrypted2 = storage.encryptCredentials(plaintext.clone());

        // Should produce different ciphertexts due to random IV
        assertFalse(Arrays.equals(encrypted1, encrypted2), "Different encryptions should produce different ciphertexts");

        // But both should decrypt to same plaintext
        char[] decrypted1 = storage.decryptCredentials(encrypted1);

        // Results should be different
        boolean different = false;
        for (int i = 0; i < result1.length; i++) {
            if (result1[i] != result2[i]) {
                different = true;
                break;
            }
        }
        assertEquals(true, different, "Different keys should produce different HMAC values");
    }

    @Test

        Instant monotonic = MonotonicClock.now();
        Instant system = Instant.now();

        // The difference should be relatively small (allow for 1 second max)
        Duration difference = Duration.between(monotonic, system).abs();
        assertTrue(difference.getSeconds() <= 1, "Monotonic time should be reasonably aligned with system time");
    }

        assertEquals(32, derived3.length, "Derived key should have correct length");

        assertFalse(Arrays.equals(derived1, derived2), "Different labels should produce different keys");
        assertFalse(Arrays.equals(derived1, derived3), "Different contexts should produce different keys");
    }

    @Test
    public void testStoreNullKey() {

func (set TargetIDSet) Union(sset TargetIDSet) TargetIDSet {
	nset := set.Clone()

	for k := range sset {
		nset.add(k)
	}

	return nset
}

// Difference - returns difference with given set as new set.
func (set TargetIDSet) Difference(sset TargetIDSet) TargetIDSet {
	nset := NewTargetIDSet()
	for k := range set {
		if _, ok := sset[k]; !ok {
			nset.add(k)
		}
	}

	return nset
}

## Origin { #origin }

An origin is the combination of protocol (`http`, `https`), domain (`myapp.com`, `localhost`, `localhost.tiangolo.com`), and port (`80`, `443`, `8080`).

So, all these are different origins:

* `http://localhost`
* `https://localhost`
* `http://localhost:8080`

import java.util.ArrayDeque;
import java.util.Iterator;
import java.util.Queue;
import java.util.concurrent.ConcurrentLinkedQueue;

/**
 * Handler for dispatching events to subscribers, providing different event ordering guarantees that
 * make sense for different situations.
 *
 * <p><b>Note:</b> The dispatcher is orthogonal to the subscriber's {@code Executor}. The dispatcher

        // Assert
        assertArrayEquals(expected, actual, "NT hash must match known test vector");
    }

    @Test
    @DisplayName("getNTHash: verify different passwords produce different hashes")
    void testGetNTHash_differentPasswords() {
        // Arrange
        String password1 = "password";
        String password2 = "Password";

        // Act

        }
    }

    @Nested
    @DisplayName("Cross-Implementation Tests")
    class CrossImplementationTests {

        @Test
        @DisplayName("Should have different context types for different implementations")
        void testDifferentContextTypes() {
            PreauthIntegrityNegotiateContext preauth = new PreauthIntegrityNegotiateContext();