assertEquals(ImmutableSet.of(), i.next());
    assertEquals(ImmutableSet.of(1), i.next());
    assertEquals(ImmutableSet.of(2), i.next());
    assertEquals(ImmutableSet.of(2, 1), i.next());
    assertEquals(ImmutableSet.of(3), i.next());
    assertEquals(ImmutableSet.of(3, 1), i.next());
    assertEquals(ImmutableSet.of(3, 2), i.next());
    assertEquals(ImmutableSet.of(3, 2, 1), i.next());
    assertFalse(i.hasNext());

    Entry<String, Integer> entry = entries.next();
    assertEquals("bar", entry.getKey());
    assertEquals(1, (int) entry.getValue());
    entry = entries.next();
    assertEquals("foo", entry.getKey());
    assertEquals(2, (int) entry.getValue());
    entry.setValue(4);
    entry = entries.next();
    assertEquals("bar", entry.getKey());
    assertEquals(3, (int) entry.getValue());

	if err == io.EOF {
		err = io.ErrUnexpectedEOF
	}
	r.err = err
	return r.current, err
}

// next will read one entry from the stream.
// Generally not recommended for fast operation.
func (r *metacacheReader) next() (metaCacheEntry, error) {
	r.checkInit()
	if r.err != nil {
		return metaCacheEntry{}, r.err
	}
	var m metaCacheEntry
	var err error

But first, let's check some small concepts.

## In a hurry?

If you don't care about any of these terms and you just need to add security with authentication based on username and password *right now*, skip to the next chapters.

## OAuth2

OAuth2 is a specification that defines several ways to handle authentication and authorization.

It is quite an extensive specification and covers several complex use cases.

    }.test();
  }

  public void testIteratorNoSuchElementException() {
    Iterator<E> iterator = collection.iterator();
    while (iterator.hasNext()) {
      iterator.next();
    }

    assertThrows(NoSuchElementException.class, () -> iterator.next());
  }

    /**
     * @return the expiration time of this entry
     */
    long getExpiration ();


    /**
     * 
     * @return pointer to next referral, points to self if there is no further referral
     */
    DfsReferralData next ();


    /**
     * @return the link
     */
    String getLink ();

            return i < array.length;
          }

          @Override
          public String next() {
            if (!hasNext()) {
              throw new NoSuchElementException();
            }
            return array[i++];
          }
        };

    assertTrue(iterator.hasNext());
    assertEquals("a", iterator.next());
    assertThrows(UnsupportedOperationException.class, () -> iterator.remove());
  }

$(function() {
  $('input[type="text"],select,textarea', ".login-box,section.content")
    .first()
    .focus();
  $(".form-group .has-error")
    .first()
    .next("input,select,textarea")
    .focus();

  $("section.content input").keypress(function(e) {
    var $submitButton;
    if (e.which === 13) {
      $submitButton = $("input#submit, button#submit");
      if ($submitButton.length > 0) {
        $submitButton[0].submit();
      }

import java.util.function.Function;
import java.util.function.Supplier;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Tester for {@code Spliterator} implementations.
 *
 * @since NEXT (but since 21.0 in the JRE flavor)
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
@SuppressWarnings("Java7ApiChecker")
@IgnoreJRERequirement // Users will use this only if they're already using Spliterator.

  }

  @CollectionFeature.Require({SUPPORTS_ADD, FAILS_FAST_ON_CONCURRENT_MODIFICATION})
  public void testSetCountZeroToOneConcurrentWithEntrySetIteration() {
    Iterator<Entry<E>> iterator = getMultiset().entrySet().iterator();
    assertSetCount(e3(), 1);
    assertThrows(ConcurrentModificationException.class, () -> iterator.next());
  }