)

	r := newMockReader(failAfter, mockData)
	scanner := newScanner(r)

	for i < 1000 {
		c := scanner.next()
		if c == byte(0) {
			break
		}
		if c != mockData {
			t.Fatalf("expected \"%s\", got \"%s\"", string(mockData), string(c))
		}
		i++
	}
	c := scanner.next()
	if scanner.readerErr == nil {
		t.Fatalf("failed to receive expected error after %d bytes", failAfter)
	}
	if c != byte(0) {

    Iterator<Entry<E>> entryIterator = entryIterator();
    return entryIterator.hasNext() ? entryIterator.next() : null;
  }

  @Override
  public @Nullable Entry<E> lastEntry() {
    Iterator<Entry<E>> entryIterator = descendingEntryIterator();
    return entryIterator.hasNext() ? entryIterator.next() : null;
  }

  @Override
  public @Nullable Entry<E> pollFirstEntry() {

    int i = 0;
    while (expectedIterator.hasNext()) {
      Object expected = expectedIterator.next();

      assertTrue(
          "index " + i + " expected <" + expected + "., actual is exhausted",
          actualIterator.hasNext());

      Object actual = actualIterator.next();
      assertEquals("index " + i, expected, actual);
      i++;
    }
    if (actualIterator.hasNext()) {

     */
    @Override
    public void prepare(final CommonServerMessageBlockRequest next) {
        if (isReceived() && next instanceof RequestWithFileId) {
            ((RequestWithFileId) next).setFileId(this.fileId);
        }
        super.prepare(next);
    }

    /**
     * Get the oplock level granted by the server
     * @return the oplockLevel
     */

    }

    /**
     * Returns true if a next page exists.
     *
     * @return True if a next page exists.
     */
    public boolean isExistNextPage() {
        return existNextPage;
    }

    /**
     * Sets whether a next page exists.
     *
     * @param existNextPage True if a next page exists.
     */
    public void setExistNextPage(final boolean existNextPage) {

     * stack so that it is returned by the next call to {@link Iterator#next()}. If the element is
     * not in {@link #nextElements}, this method throws an {@link UnknownElementException}.
     *
     * <p>This method is used when testing iterators without a known ordering. We poll the target
     * iterator's next element and pass it to the reference iterator through this method so it can

    Iterator<String> keyIterator = keys.iterator();
    keyIterator.next();
    keyIterator.remove();
    assertFalse(underlying.containsKey("c"));

    Collection<String> values = map.values();
    values.remove("4");
    assertFalse(underlying.containsKey("d"));

    Iterator<String> valueIterator = values.iterator();
    valueIterator.next();
    valueIterator.remove();
    assertFalse(underlying.containsKey("e"));

    }

    public boolean isEmpty() {
        return pos == input.length();
    }

    public void mark() {
        markPos = pos;
    }

    public void next() {
        next(1);
    }

    public void next(int n) {
        pos += n;
    }

    public boolean lookingAt(char c) {
        return input.charAt(pos) == c;
    }

    public boolean lookingAt(CharSequence prefix) {

The main [Tutorial - User Guide](../tutorial/index.md) should be enough to give you a tour through all the main features of **FastAPI**.

In the next sections you will see other options, configurations, and additional features.

/// tip

The next sections are **not necessarily "advanced"**.

And it's possible that for your use case, the solution is in one of them.

///

        assertSame(fe1, it.next(), "First element must match first page");
        assertTrue(it.hasNext(), "Iterator should have second element");
        assertSame(fe2, it.next(), "Second element must match first page");

        // Next page fetched via fetchMore()
        assertTrue(it.hasNext(), "Iterator should have third element after fetchMore");
        assertSame(fe3, it.next(), "Third element from second page");