}
    }

    // Test property key with dots
    public void test_get_propertyKeyWithDots() {
        String dottedKey = "deeply.nested.property.key";
        String dottedValue = "nested-value";

        System.setProperty(Constants.FESS_CONFIG_PREFIX + dottedKey, dottedValue);

        try {
            String value = fessConfig.get(dottedKey);

import java.io.ByteArrayOutputStream;
import java.io.PrintStream;

import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Nested;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.mockito.Mock;
import org.mockito.junit.jupiter.MockitoExtension;

/**
 * JUnit 5 tests for {@link TestLocking}.

 * <p>
 * Beans injected into Mojo parameters are prepared by <a href="https://www.eclipse.org/sisu/">Sisu</a> JSR330-based
 * container: this annotation is only effective on fields of the Mojo class itself, nested bean injection
 * requires Sisu or JSR330 annotations.
 *
 * @since 4.0.0
 */
@Experimental
@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.FIELD, ElementType.METHOD})
@Inherited

import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;

import java.util.Arrays;

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Nested;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.CsvSource;
import org.mockito.ArgumentCaptor;

import org.ietf.jgss.GSSName;
import org.ietf.jgss.Oid;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Nested;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.MethodSource;
import org.mockito.Mock;

        assertTrue(duration < 1000, "Creating and using 10000 EmptyIterators should be fast (took " + duration + "ms)");
    }

    @Test
    @DisplayName("EmptyIterator should work correctly in nested iteration")
    void testNestedIteration() {
        // When & Then
        assertDoesNotThrow(() -> {
            int outerCount = 0;
            while (emptyIterator.hasNext()) {

    version of the library.

5.  Our classes are not designed to protect against a malicious caller. You
    should not use them for communication between trusted and untrusted code.

6.  For the mainline flavor, we test the libraries using OpenJDK 8, 11, and 17
    on Linux, with some additional testing on newer JDKs and on Windows. Some

        assertEquals(longMessage, exception.getMessage());
        assertNull(exception.getCause());
    }

    public void test_constructor_withNestedCause() {
        // Test constructor with nested exception causes
        Exception rootCause = new IllegalStateException("Root cause");
        Exception middleCause = new RuntimeException("Middle cause", rootCause);
        String message = "Top level dictionary error";

        mockPipeIn.lock = new Object();

        byte[] buffer = new byte[10];
        int bufferIndex = 0;
        int len = 10;

        // Call the method to be tested
        int result = response.readDataWireFormat(buffer, bufferIndex, len);

        // Verify the result
        assertEquals(len, result, "readDataWireFormat should return the length of data read.");

Just functions that look the same as the *path operation functions*.

But still, it is very powerful, and allows you to declare arbitrarily deeply nested dependency "graphs" (trees).

/// tip

All this might not seem as useful with these simple examples.

But you will see how useful it is in the chapters about **security**.