*** DefaultLifecycleExecutor

  When binding goals to the project's configured lifecycle, each mojo
  descriptor should declare whether it requires online/offline status.
  This value should be a java.lang.Boolean, so it can implement 3VL
  (three value logic: yes, no, don't-care). The requiresOnline
  field in the mojo descriptor has the following semantics:

  [true] Online status is required for this mojo to function
         correctly.

 * states it cannot ever leave them.
 *
 * <p>Implementors of this interface are strongly encouraged to extend one of the abstract classes
 * in this package which implement this interface and make the threading and state management
 * easier.
 *
 * @author Jesse Wilson
 * @author Luke Sandberg
 * @since 9.0 (in 1.0 as {@code com.google.common.base.Service})
 */

But it provides you the tools to simplify the process as much as possible without compromising flexibility, robustness, or security.

And you can use and implement secure, standard protocols, like OAuth2 in a relatively simple way.

 * @param <R> the return type of (or supertype thereof) the method or the declaring type of the
 *     constructor.
 * @author Ben Yu
 * @since 14.0 (no longer implements {@link AccessibleObject} or {@code GenericDeclaration} since
 *     31.0)
 */
public abstract class Invokable<T, R> implements AnnotatedElement, Member {
  private final AccessibleObject accessibleObject;
  private final Member member;

  }

  public static <K, V> ImmutableSortedMap<K, V> copyOfSorted(SortedMap<K, ? extends V> map) {
    // If map has a null comparator, the keys should have a natural ordering,
    // even though K doesn't explicitly implement Comparable.
    @SuppressWarnings("unchecked")
    Comparator<? super K> comparator =
        (map.comparator() == null) ? (Comparator<? super K>) NATURAL_ORDER : map.comparator();
    return copyOfInternal(map, comparator);

	case sqlFnLower:
		return lowerCase(argVals[0])

	case sqlFnUpper:
		return upperCase(argVals[0])

	case sqlFnUTCNow:
		return handleUTCNow()

	case sqlFnToString, sqlFnToTimestamp:
		// TODO: implement
		fallthrough

	default:
		return nil, errNotImplemented
	}
}

func coalesce(args []*Value) (res *Value, err error) {
	for _, arg := range args {
		if arg.IsNull() {
			continue
		}

 * convenient shortcut methods defined directly on {@link HashFunction} to make this easier.
 *
 * <p>Hasher accepts primitive data types, but can also accept any Object of type {@code T} provided
 * that you implement a {@link Funnel}{@code <T>} to specify how to "feed" data from that object
 * into the function. (See {@linkplain Hasher#putObject an example} of this.)
 *

 * convenient shortcut methods defined directly on {@link HashFunction} to make this easier.
 *
 * <p>Hasher accepts primitive data types, but can also accept any Object of type {@code T} provided
 * that you implement a {@link Funnel}{@code <T>} to specify how to "feed" data from that object
 * into the function. (See {@linkplain Hasher#putObject an example} of this.)
 *

// DecompressedSize - For compressed objects.
func (r *Reader) ActualSize() int64 { return r.actualSize }

// ETag returns the ETag computed by an underlying etag.Tagger.
// If the underlying io.Reader does not implement etag.Tagger
// it returns nil.
func (r *Reader) ETag() etag.ETag {
	if t, ok := r.src.(etag.Tagger); ok {
		return t.ETag()
	}
	return nil
}

// MD5Current returns the MD5 checksum of the content

 * set to {@code true} grants threads access in FIFO order. Fairness generally decreases throughput
 * but reduces variability and avoids starvation.
 *
 * <p>This class and its iterator implement all of the optional methods of the {@link
 * Collection} and {@link Iterator} interfaces.
 *
 * @author Doug Lea
 * @author Justin T. Sampson
 * @param <E> the type of elements held in this collection
 */