* Select "Python"
* Run the debugger with the option "`Python: Current File (Integrated Terminal)`".

It will then start the server with your **FastAPI** code, stop at your breakpoints, etc.

Here's how it might look:

<img src="/img/tutorial/debugging/image01.png">

---

If you use Pycharm, you can:

* Open the "Run" menu.
* Select the option "Debug...".
* Then a context menu shows up.

* **Modify some DNS records**.
    * For this, the renewal program needs to support the APIs of the DNS provider, so, depending on the DNS provider you are using, this might or might not be an option.
* **Run as a server** (at least during the certificate acquisition process) on the public IP address associated with the domain.
    * As we said above, only one process can be listening on a specific IP and port.

        // Test convert with null text - this might throw exception
        String text = null;
        String field = "content";

        try {
            List<String> results = converter.convert(text, field, "en");
            assertNotNull(results);
        } catch (Exception e) {
            // Expected behavior - null text might cause exception
            assertNotNull(e);
        }
    }

        problem = new DefaultProblem(null, null, null, Integer.MAX_VALUE, -1, null);
        assertEquals(Integer.MAX_VALUE, problem.getLineNumber());

        // this case is not specified, might also return -1
        problem = new DefaultProblem(null, null, null, Integer.MIN_VALUE, -1, null);
        assertEquals(Integer.MIN_VALUE, problem.getLineNumber());
    }

    @Test
    void testGetColumnNumber() {

I say--that's the same thing, you know.'

  `Not the same thing a bit!' said the Hatter.  `You might just
as well say that "I see what I eat" is the same thing as "I eat
what I see"!'

  `You might just as well say,' added the March Hare, `that "I
like what I get" is the same thing as "I get what I like"!'

  `You might just as well say,' added the Dormouse, who seemed to

            if (testTransport == null) {
                // No recovery possible, remove synchronously
                removeChannel(failedChannel);
                return;
            }
            // Recovery might be viable, attempt it with pre-created transport
            if (state.shouldRetry()) {
                scheduleRecoveryWithTransport(failedChannel, state, testTransport);
            } else {

    features.add(CollectionFeature.SUBSET_VIEW);
    if (features.remove(CollectionFeature.ALLOWS_NULL_VALUES)) {
      // the null value might be out of bounds, so we can't always construct a subset with nulls
      features.add(CollectionFeature.ALLOWS_NULL_QUERIES);
      // but add null might still be supported if it happens to be within range of the subset
      suppressing.add(CollectionAddTester.getAddNullUnsupportedMethod());

you unpack it into /usr/local/go, or if you rebuild from sources by running all.bash (see doc/install.html). You should also add the Go binary directory $GOROOT/bin to your shell's path. For example, if you extracted the tar file into $HOME/go, you might put the following in your .profile: export GOROOT=$HOME/go export PATH=$PATH:$GOROOT/bin See doc/install.html for more details....

    if (supportsRemove) {
      // We use a copy of "entryToRemove" in the assertion because "entryToRemove" might be
      // invalidated and have undefined behavior after entrySet.removeAll(entriesToRemove),
      // for example entryToRemove.getValue() might be null.
      Entry<K, V> entryToRemoveCopy = mapEntry(entryToRemove.getKey(), entryToRemove.getValue());

      int initialSize = map.size();

If something seems interesting and useful to your project, go ahead and check it, but otherwise, you might probably just skip them.

/// tip

If you want to **learn FastAPI** in a structured way (recommended), go and read the [Tutorial - User Guide](../tutorial/index.md){.internal-link target=_blank} chapter by chapter instead.