} else {
      int k = 20;
      return BigInteger.valueOf(LongMath.factorial(k)).multiply(oldSlowFactorial(k, n));
    }
  }

  /** Returns the product of {@code n1} exclusive through {@code n2} inclusive. */
  @SuppressWarnings("UseCorrectAssertInTests") // TODO(b/345814817): Remove or convert assertion.
  private static BigInteger oldSlowFactorial(int n1, int n2) {
    assert n1 <= n2;

 *
 * <p>For example, this expression:
 *
 * <pre>{@code
 * Splitter.on(',').split("foo,bar,qux")
 * }</pre>
 *
 * ... produces an {@code Iterable} containing {@code "foo"}, {@code "bar"} and {@code "qux"}, in
 * that order.
 *
 * <p>By default, {@code Splitter}'s behavior is simplistic and unassuming. The following
 * expression:
 *
 * <pre>{@code
 * Splitter.on(',').split(" foo,,,  bar ,")
 * }</pre>
 *

   *     was indeed modified, unless {@code oldCount == newCount}.
   * @throws IllegalArgumentException if {@code oldCount} or {@code newCount} is negative
   * @throws NullPointerException if {@code element} is null and the implementation does not permit
   *     null elements. Note that if {@code oldCount} and {@code newCount} are both zero, the
   *     implementor may optionally return {@code true} instead.
   */
  @CanIgnoreReturnValue

 */
@ThreadSafe
public interface Mojo {
    /** The component <code>role</code> hint for Plexus container */
    String ROLE = Mojo.class.getName();

    /**
     * Perform whatever build-process behavior this <code>Mojo</code> implements.<br>
     * This is the main trigger for the <code>Mojo</code> inside the <code>Maven</code> system, and allows
     * the <code>Mojo</code> to communicate errors.
     *

     * @param globalSettingsSource The global settings source, may be {@code null} to disable global settings.
     * @return This request, never {@code null}.
     */
    SettingsBuildingRequest setGlobalSettingsSource(SettingsSource globalSettingsSource);

    /**
     * Gets the project settings file.
     *
     * @return The project settings file or {@code null} if none.
     * @since 4.0.0
     */
    File getProjectSettingsFile();

Most source code in Gradle is arranged by which part(s) of the build state model it acts on.
This affects the lifecycle of the code and the set of services available for dependency injection.
When working on some source code it is important to be aware of the model it acts on.  

import com.google.common.base.Objects;
import java.util.Map.Entry;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Implementation of the {@code equals}, {@code hashCode}, and {@code toString} methods of {@code
 * Entry}.
 *
 * @author Jared Levy
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
abstract class AbstractMapEntry<K extends @Nullable Object, V extends @Nullable Object>

     *
     * @return The type of the event, never {@code null}.
     */
    Type getType();

    /**
     * Gets the session from which this event originates.
     *
     * @return The current session, never {@code null}.
     */
    MavenSession getSession();

    /**
     * Gets the current project (if any).
     *
     * @return The current project or {@code null} if not applicable.
     */

import com.google.common.base.Objects;
import java.util.Map.Entry;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Implementation of the {@code equals}, {@code hashCode}, and {@code toString} methods of {@code
 * Entry}.
 *
 * @author Jared Levy
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
abstract class AbstractMapEntry<K extends @Nullable Object, V extends @Nullable Object>

 * and the field type can be {@link org.apache.maven.api.Node Node},
 * {@code List<}{@link org.apache.maven.api.Node Node}{@code >},
 * {@link org.apache.maven.api.services.DependencyResolverResult DependencyResolverResult},
 * {@code List<}{@link java.nio.file.Path Path}{@code >},