* @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 MetadataParseException(String message, int lineNumber, int columnNumber, Throwable cause) {
        super(message);
        initCause(cause);

import java.time.Clock;
import java.time.Duration;
import java.time.Instant;
import java.time.ZoneId;
import java.time.ZoneOffset;

import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Nested;
import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNotNull;
import static org.junit.jupiter.api.Assertions.assertSame;

 * <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

    void putLongLittleEndian(byte[] array, int offset, long value);

    boolean usesFastPath();
  }

  /**
   * The only reference to Unsafe is in this nested class. We set things up so that if
   * Unsafe.theUnsafe is inaccessible, the attempt to load the nested class fails, and the outer
   * class's static initializer can fall back on a non-Unsafe version.
   */
  @SuppressWarnings("SunApi") // b/345822163
  @VisibleForTesting

     * @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 ToolchainsParseException(String message, int lineNumber, int columnNumber, Throwable cause) {
        super(message);
        initCause(cause);

    public void setGroupCacheExpiry(final long groupCacheExpiry) {
        this.groupCacheExpiry = groupCacheExpiry;
    }

    /**
     * Sets the maximum group depth for nested group processing.
     * @param maxGroupDepth The maximum depth for nested groups.
     */
    public void setMaxGroupDepth(final int maxGroupDepth) {
        this.maxGroupDepth = maxGroupDepth;
    }

    @Override

        assertEquals(0, SessionSetupHandler.class.getDeclaredFields().length, "No fields expected");
        assertEquals(0, SessionSetupHandler.class.getDeclaredClasses().length, "No nested types expected");
    }

    @ParameterizedTest(name = "Implementation is instance: {0}")
    @MethodSource("implementations")
    @DisplayName("Happy path: can create implementations and use type checks")

      if (!GUAVA_PACKAGES.contains(info.getPackageName())) {
        continue;
      }
      if (
      /*
       * At least one of the classes nested inside TypeResolverTest triggers a bug under older JDKs:
       * https://bugs.openjdk.org/browse/JDK-8215328 -> https://bugs.openjdk.org/browse/JDK-8215470

            // 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) {

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**.