return value;
      }
    };
  }

  private static <K extends @Nullable Object, V extends @Nullable Object> Entry<K, V> control(
      K key, V value) {
    return singletonMap(key, value).entrySet().iterator().next();
  }

  public void testToString() {
    assertEquals("foo=1", entry("foo", 1).toString());
  }

  public void testToStringNull() {
    assertEquals("null=1", entry(NK, 1).toString());

  /**
   * Precondition tester for {@code Iterator.remove()} that throws an exception with a consistent
   * error message.
   */
  static void checkRemove(boolean canRemove) {
    checkState(canRemove, "no calls to next() since the last call to remove()");
  }

  private CollectPreconditions() {}

        throw new ClUnsupportedOperationException("remove");
    }

    @Override
    public boolean hasNext() {
        return enumeration.hasMoreElements();
    }

    @Override
    public T next() {
        return enumeration.nextElement();
    }

And it should have an `access_token`, with a string containing our access token.

For this simple example, we are going to just be completely insecure and return the same `username` as the token.

/// tip

In the next chapter, you will see a real secure implementation, with password hashing and <abbr title="JSON Web Tokens">JWT</abbr> tokens.

But for now, let's focus on the specific details we need.

///

        vector.add("a");
        final EnumerationIterator<String> itr = new EnumerationIterator<String>(vector.elements());
        assertThat(itr.hasNext(), is(true));
        assertThat(itr.next(), is("a"));
        assertThat(itr.hasNext(), is(not(true)));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testRemove() throws Exception {

    @Override
    public boolean hasNext() {
        if (line == EMPTY) {
            line = ReaderUtil.readLine(reader);
        }
        return line != null;
    }

    @Override
    public String next() {
        if (!hasNext()) {
            throw new NoSuchElementException();
        }
        final String result = line;
        line = EMPTY;
        return result;
    }

    @Override

        this.classLoader = classLoader;
    }

    @Override
    public boolean hasNext() {
        return classLoader != null;
    }

    @Override
    public ClassLoader next() {
        if (!hasNext()) {
            throw new NoSuchElementException();
        }
        final ClassLoader result = classLoader;
        classLoader = classLoader.getParent();
        return result;
    }

type GetDBConnector interface {
	GetDBConn() (*sql.DB, error)
}

// Rows rows interface
type Rows interface {
	Columns() ([]string, error)
	ColumnTypes() ([]*sql.ColumnType, error)
	Next() bool
	Scan(dest ...interface{}) error
	Err() error
	Close() error
}

type ErrorTranslator interface {
	Translate(err error) error

default(Z).each((function(e,t){var a=n.default(t).attr(ee),i=n.default(t).next(Y).children().first().children();"true"===a?i.show():"false"===a&&(i.hide(),i.parent().parent().addClass("d-none"))}))},t.toggleRow=function(){var e=this._element;"TR"!==e[0].nodeName&&"TR"!==(e=e.parent())[0].nodeName&&(e=e.parent());var t=e.attr(ee),a=e.next(Y).children().first().children();a.stop(),"true"===t?(a.slideUp(500,(function(){e.next(Y).addClass("d-none")})),e.attr(ee,"false"),e.trigger(n.default.Event("co...

        ConcurrentModificationException.class,
        () -> {
          Iterator<E> iterator = collection.iterator();
          assertTrue(collection.removeIf(Predicate.isEqual(samples.e0())));
          iterator.next();
        });
  }

  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)
  public void testRemoveIf_unsupportedEmptyCollection() {
    try {
      assertFalse(