### The Problem { #the-problem }

So, what's the problem with installing packages in the global Python environment?

At some point, you will probably end up writing many different programs that depend on **different packages**. And some of these projects you work on will depend on **different versions** of the same package. 😱

Lembre-se de como nossa estrutura app/file se parece:

<img src="/img/tutorial/bigger-applications/package.drawio.svg">

---

Os dois pontos `..`, como em:

```Python
from ..dependencies import get_token_header
```

significa:

E também que o seu código será muito compatível com diversas outras ferramentas e bibliotecas Python. 🚀

///

## Type hints no **FastAPI** { #type-hints-in-fastapi }

O **FastAPI** aproveita esses type hints para fazer várias coisas.

Com o **FastAPI**, você declara parâmetros com type hints e obtém:

* **Suporte ao editor**.
* **Verificações de tipo**.

... e o **FastAPI** usa as mesmas declarações para:

   * references to the map or modify it in any way.
   *
   * <p>The returned multiset is serializable if the input map is.
   *
   * @param countMap backing map for storing the elements in the multiset and their counts. It must
   *     be empty.
   * @throws IllegalArgumentException if {@code countMap} is not empty
   * @since 20.0
   */
  public static <E> ConcurrentHashMultiset<E> create(ConcurrentMap<E, AtomicInteger> countMap) {

    - [Container Images](#container-images-16)
  - [Changelog since v1.26.0](#changelog-since-v1260)
  - [Known Issues](#known-issues)
    - [The PreEnqueue extension point doesn't work for Pods going to activeQ through backoffQ](#the-preenqueue-extension-point-doesnt-work-for-pods-going-to-activeq-through-backoffq)
  - [Urgent Upgrade Notes](#urgent-upgrade-notes)

        // Create the transport with safe defaults (no real sockets)
        transport = new SmbTransportImpl(ctx, address, 445, null, 0, false);

        // Reset MID to a known starting point for deterministic behavior
        setField(transport, "mid", new AtomicLong());
    }

    // Utility: reflectively set a private/protected field (searches up the hierarchy)

                extensionRecord = setupExtensionsRealm(project, plugin, repositorySession);
            } catch (PluginManagerException e) {
                // extensions realm is expected to be fully setup at this point
                // any exception means a problem in maven code, not a user error
                throw new IllegalStateException(e);
            }

            ClassRealm pluginRealm = extensionRecord.getRealm();

            return baos.toByteArray();
        } catch (IOException e) {
            throw new CIFSException("LZ77+Huffman decompression failed", e);
        }
    }

    /**
     * Counts the number of unique bytes in the data (for entropy estimation).
     */
    private int countUniqueBytes(byte[] data) {
        boolean[] seen = new boolean[256];
        int count = 0;

    int size = 0;
    for (Multiset.Entry<E> entry : getMultiset().entrySet()) {
      size += entry.getCount();
    }
    assertEquals(
        "multiset.size() should be the sum of the counts of all entries",
        size,
        getMultiset().size());
  }

  /** Call the {@code setCount()} method under test, and check its return value. */
  abstract void setCountCheckReturnValue(E element, int count);

///

## Подприложения { #sub-applications }