We are going to include this `APIRouter` in the main `FastAPI` app, but first, let's check the dependencies and another `APIRouter`.

## Dependencies

We see that we are going to need some dependencies used in several places of the application.

So we put them in their own `dependencies` module (`app/dependencies.py`).

    // cheats and does not attempt every possible permutation. Instead, it only considers wildcards
    // in the leftmost position. We assert this fact when we generate the public suffix file. If
    // this assertion ever fails we'll need to refactor this implementation.
    var wildcardMatch: String? = null
    if (domainLabelsUtf8Bytes.size > 1) {
      val labelsWithWildcard = domainLabelsUtf8Bytes.clone()

        // If we are at a super-type constructor call, adjust the resolution expression so that we
        // get the constructor instead of the class.
        //
        // For the example:
        //
        // class A {
        //   constructor()
        // }
        // class B: <caret>A()
        //

    //     we find them, regardless of what the address policies need.
    //
    //  2. EVICTABLE: Connections not required by any address policy. This matches connections that
    //     don't participate in any policy, plus connections whose policies won't be violated if the
    //     connection is closed. We only close these if the idle connection limit is exceeded.
    //

        }

        if (errorExceptionToDeliver != null) {
          // We defer throwing the exception until now so that we can refill the connection
          // flow-control window. This is necessary because we don't transmit window updates until
          // the application reads the data. If we throw this prior to updating the connection
          // flow-control window, we risk having it go to 0 preventing the server from sending data.

Free Software Foundation and other authors who decide to use it.  You
can use it too, but we suggest you first think carefully about whether
this license or the ordinary General Public License is the better
strategy to use in any particular case, based on the explanations below.

  When we speak of free software, we are referring to freedom of use,
not price.  Our General Public Licenses are designed to make sure that

    if (entry != null && entry.lockingSourceCount != 0) {
      return null // We can't write this file because a reader is still reading it.
    }

    if (mostRecentTrimFailed || mostRecentRebuildFailed) {
      // The OS has become our enemy! If the trim job failed, it means we are storing more data than
      // requested by the user. Do not allow edits so we do not go over that limit any further. If

### We Make Mistakes

We, as humans, make **mistakes**, all the time. Software almost *always* has **bugs** hidden in different places. 🐛

And we as developers keep improving the code as we find those bugs and as we implement new features (possibly adding new bugs too 😅).

### Small Errors Automatically Handled

    }
    body.awaitSuccess()
  }

  /**
   * Duplex calls that have follow-ups are weird. By the time we know there's a follow-up we've
   * already split off another thread to stream the request body. Because we permit at most one
   * exchange at a time we break the request stream out from under that writer.
   */
  @Test
  fun duplexWithRedirect() {
    enableProtocol(Protocol.HTTP_2)

  /**
   * Consume the next header in the stream and return it. If there is no header to read because we
   * have reached a limit, this returns [END_OF_DATA].
   */
  internal fun readHeader(): DerHeader {
    require(peekedHeader == null)

    // We've hit a local limit.
    if (byteCount == limit) return END_OF_DATA

    // We've exhausted the source stream.
    if (limit == -1L && source.exhausted()) return END_OF_DATA