void testDcerpcFaultInvalidTag() {
        assertEquals(0x1C000006, DcerpcError.DCERPC_FAULT_INVALID_TAG);
    }

    @Test
    @DisplayName("Should verify DCERPC_FAULT_CONTEXT_MISMATCH constant value")
    void testDcerpcFaultContextMismatch() {
        assertEquals(0x1C00001A, DcerpcError.DCERPC_FAULT_CONTEXT_MISMATCH);
    }

    @Test

        assertTrue(config.isUseRDMA(), "RDMA should be enabled");
        assertEquals("disni", config.getRdmaProvider(), "Provider should be disni");
        assertEquals(16384, config.getRdmaReadWriteThreshold(), "Threshold should be 16KB");
        assertEquals(131072, config.getRdmaMaxSendSize(), "Max send size should be 128KB");
        assertEquals(131072, config.getRdmaMaxReceiveSize(), "Max receive size should be 128KB");

        // Then - Buffer should have expected size
        assertNotNull(buffer, "Buffer should not be null");
        assertEquals(SmbComTransaction.TRANSACTION_BUF_SIZE, buffer.length, "Buffer should have TRANSACTION_BUF_SIZE");

        // The validation in getBuffer() ensures size is within bounds (0 < size <= 1MB)
        assertTrue(buffer.length > 0, "Buffer size should be positive");

In this case, you could want to document how that external API *should* look like. What *path operation* it should have, what body it should expect, what response it should return, etc.

## An app with callbacks { #an-app-with-callbacks }

Let's see all this with an example.

Imagine you develop an app that allows creating invoices.

       * that behavior is undefined when the backing map is modified through another API. (It even
       * permits us to throw IllegalStateException. Maybe we should have done that, but we probably
       * shouldn't change now for fear of breaking people.)
       */
      return (lastKnownIndex == -1) ? unsafeNull() : value(lastKnownIndex);
    }

    @Override
    @ParametricNullness

        assertTrue(decoded > 0, "Decode should return positive length");

        assertEquals(NtStatus.NT_STATUS_MORE_PROCESSING_REQUIRED, resp.getStatus());
        assertArrayEquals(blob, resp.getBlob(), "Security blob should match");
        assertEquals(sessionFlags, resp.getSessionFlags(), "Session flags should decode");
        assertTrue(resp.isLoggedInAsGuest(), "Guest/anonymous should be detected");

        assertEquals(fileName, notifications.get(0).getFileName());
    }

    @Test
    @DisplayName("Should test isErrorResponseStatus with various status codes")
    void testIsErrorResponseStatus() throws Exception {
        // Test with NT_STATUS_NOTIFY_ENUM_DIR - should not be error
        setStatus(response, NtStatus.NT_STATUS_NOTIFY_ENUM_DIR);
        assertFalse(response.isErrorResponseStatus());

        String hostName = mockAddress.getHostName();

        // Then
        assertEquals(expectedHostName, hostName, "Should return configured hostname");
        assertNotNull(hostName, "Host name should not be null");
    }

    @Test
    @DisplayName("getHostAddress should return valid IP address string")
    void testGetHostAddressContract() {
        // Given
        String expectedAddress = "192.168.1.100";

        getMethodName() + "(firstElement) should return 0", 0, find(getOrderedElements().get(0)));
  }

  public void testFind_no() {
    assertEquals(getMethodName() + "(notPresent) should return -1", -1, find(e3()));
  }

  @CollectionFeature.Require(ALLOWS_NULL_VALUES)
  public void testFind_nullNotContainedButSupported() {
    assertEquals(getMethodName() + "(nullNotPresent) should return -1", -1, find(null));
  }

    assertTrue("contains(present) should return true", collection.contains(e0()));
  }

  public void testContains_no() {
    assertFalse("contains(notPresent) should return false", collection.contains(e3()));
  }

  @CollectionFeature.Require(ALLOWS_NULL_QUERIES)
  public void testContains_nullNotContainedButQueriesSupported() {
    assertFalse("contains(null) should return false", collection.contains(null));
  }