* @param lineNumber The one-based index of the line containing the error or {@code -1} if unknown.
     * @param columnNumber The one-based index of the column containing the error or {@code -1} if unknown.
     * @param cause The nested cause of this error, may be {@code null}.
     */
    public SettingsParseException(String message, int lineNumber, int columnNumber, Throwable cause) {
        super(message);
        initCause(cause);

 * object being tested for equality to the custom interface. {@code ForwardingObject} implements no
 * such custom interfaces directly; they are implemented only in subclasses. Therefore, forwarding
 * {@code equals} would break symmetry, as the forwarding object might consider itself equal to the
 * object being tested, but the reverse could not be true. This behavior is consistent with the

 * <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

Таким чином його схема з'явиться в інтерфейсі користувача документації API:

<img src="/img/tutorial/dataclasses/image01.png">

## Dataclasses у вкладених структурах даних { #dataclasses-in-nested-data-structures }

Можна поєднувати `dataclasses` з іншими анотаціями типів, щоб створювати вкладені структури даних.

 * object being tested for equality to the custom interface. {@code ForwardingObject} implements no
 * such custom interfaces directly; they are implemented only in subclasses. Therefore, forwarding
 * {@code equals} would break symmetry, as the forwarding object might consider itself equal to the
 * object being tested, but the reverse could not be true. This behavior is consistent with the

import static org.mockito.Mockito.never;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;

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.ValueSource;

            // confirm element doesn't contain nested XML
            if (parser.next() != XmlPullParser.START_TAG) {
                return convertText(text, clazz == rawType ? toType : TypeLiteral.get(clazz));
            }
        }

        if (String.class == clazz) {
            // mimic plexus: discard any strings containing nested XML
            while (parser.getEventType() == XmlPullParser.START_TAG) {

        assertEquals("", item.getPath());
    }

    public void test_deeplyNestedPath() {
        final String deepPath = "/level1/level2/level3/level4/level5/";
        final StorageItem item = new StorageItem("nested.txt", deepPath, false, 256L, null, "bmVzdGVkLnR4dA==");

        assertEquals(deepPath, item.getPath());
    }

    public void test_specialCharactersInName() {

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

    @Test
    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";

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**.