}

  @Override
  public int nextIndex() {
    return delegate().nextIndex();
  }

  @CanIgnoreReturnValue
  @Override
  @ParametricNullness
  public E previous() {
    return delegate().previous();
  }

  @Override
  public int previousIndex() {
    return delegate().previousIndex();
  }

  @Override
  public void set(@ParametricNullness E element) {

# Classes as Dependencies { #classes-as-dependencies }

Before diving deeper into the **Dependency Injection** system, let's upgrade the previous example.

## A `dict` from the previous example { #a-dict-from-the-previous-example }

In the previous example, we were returning a `dict` from our dependency ("dependable"):

{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[9] *}

        this.allPageCount = allPageCount;
    }

    /**
     * Check if the previous page exists.
     * @return true if the previous page exists.
     */
    public boolean isExistPrePage() {
        return existPrePage;
    }

    /**
     * Set if the previous page exists.
     * @param existPrePage true if the previous page exists.
     */
    public void setExistPrePage(final boolean existPrePage) {

    }

    /**
     * Checks if there is a previous page.
     * @return True if a previous page exists, false otherwise.
     */
    public boolean isExistPrePage() {
        return existPrePage;
    }

    /**
     * Sets the existence of a previous page.
     * @param existPrePage True if a previous page exists.
     */
    public void setExistPrePage(final boolean existPrePage) {

        this.allPageCount = allPageCount;
    }

    /**
     * Checks if previous page exists.
     *
     * @return true if previous page exists
     */
    public boolean isExistPrePage() {
        return existPrePage;
    }

    /**
     * Sets whether previous page exists.
     *
     * @param existPrePage true if previous page exists
     */
    public void setExistPrePage(final boolean existPrePage) {

    }

    /**
     * Checks if a previous page exists.
     * @return true if a previous page exists, false otherwise.
     */
    public boolean isExistPrePage() {
        return existPrePage;
    }

    /**
     * Sets whether a previous page exists.
     * @param existPrePage true if a previous page exists, false otherwise.
     */

    }

    /**
     * Checks if a previous page exists.
     *
     * @return true if a previous page exists, false otherwise.
     */
    public boolean isExistPrePage() {
        return existPrePage;
    }

    /**
     * Sets the flag for the existence of a previous page.
     *
     * @param existPrePage true if a previous page exists.
     */

/// tip

Also, keep in mind that depending on your setup, in some cases you **might not even need any previous steps** before starting your application.

In that case, you wouldn't have to worry about any of this. 🤷

///

### Examples of Previous Steps Strategies { #examples-of-previous-steps-strategies }

  public void fetch(HttpUrl url) throws IOException {
    // Skip hosts that we've visited many times.
    AtomicInteger hostnameCount = new AtomicInteger();
    AtomicInteger previous = hostnames.putIfAbsent(url.host(), hostnameCount);
    if (previous != null) hostnameCount = previous;
    if (hostnameCount.getAndIncrement() >= hostLimit) return;

    Request request = new Request.Builder()
        .url(url)
        .build();

    }

    /**
     * Checks if a previous page exists.
     *
     * @return true if a previous page exists, false otherwise
     */
    public boolean isExistPrePage() {
        return existPrePage;
    }

    /**
     * Sets whether a previous page exists.
     *
     * @param existPrePage true if a previous page exists, false otherwise
     */