// Clear
	if err := DB.Model(&user2).Association("Company").Clear(); err != nil {
		t.Errorf("Error happened when clear Company, got %v", err)
	}

	if err := DB.Model(&user2).Association("Manager").Clear(); err != nil {
		t.Errorf("Error happened when clear Manager, got %v", err)
	}

	AssertAssociationCount(t, user2, "Company", 0, "after clear")

        // Clear the filter
        urlFilter.clear();

        // After clear, all URLs should match (no filters applied)
        assertTrue(urlFilter.match("https://example.com/page"));
        assertTrue(urlFilter.match("https://other.com/page"));
        assertTrue(urlFilter.match("https://any.com/image.jpg"));
    }

    /**
     * Test clear method without initialization
     */

	}

	DB.Model(&hamster).Association("PreferredToy").Clear()

	if DB.Model(&hamster2).Association("PreferredToy").Count() != 0 {
		t.Errorf("Hamster's preferred toy should be cleared with Clear")
	}

	if DB.Model(&hamster2).Association("OtherToy").Count() != 1 {
		t.Errorf("Hamster's other toy should be still available")
	}

	DB.Model(&hamster).Association("OtherToy").Clear()

Primeiro, certifique-se de criar seu [ambiente virtual](../virtual-environments.md){.internal-link target=_blank}, ativá-lo e, em seguida, instalar o `sqlmodel`:

<div class="termy">

```console
$ pip install sqlmodel
---> 100%
```

</div>

## Criar o App com um Único Modelo { #create-the-app-with-a-single-model }

Vamos criar a primeira versão mais simples do app com um único modelo **SQLModel**.

        synchronized (BeanDescFactory.class) {
            if (!initialized) {
                DisposableUtil.add(BeanDescFactory::clear);
                initialized = true;
            }
        }
    }

    /**
     * Clears the cache.
     */
    public static void clear() {
        beanDescCache.clear();
        initialized = false;
    }

    /**
     * Process an url when it's added as a seed url.
     *
     * @param url URL
     */
    void processUrl(String url);

    /**
     * Clear this filter.
     */
    void clear();

        } else {
            this.inactiveProfileIds.clear();
        }
    }

    @Override
    public void setProfiles(List<Profile> profiles) {
        if (profiles != null) {
            this.profiles = new ArrayList<>(profiles);
        } else {
            this.profiles.clear();
        }
    }

    @Override
    public void addProfile(Profile profile) {

# Subdependências { #sub-dependencies }

Você pode criar dependências que possuem **subdependências**.

Elas podem ter o nível de **profundidade** que você achar necessário.

O **FastAPI** se encarrega de resolver essas dependências.

## Primeira dependência "dependable" { #first-dependency-dependable }

Você pode criar uma primeira dependência ("dependable") dessa forma:

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[8:9] *}

     */
    public MemoryDataHelper() {
        super();
    }

    /**
     * Clears all URL queues and session data.
     */
    public void clear() {
        urlQueueMap.clear();
        sessionMap.clear();
    }

    /**
     * Returns the URL queue for the specified session ID.
     * Creates a new queue if one doesn't exist.
     * @param sessionId the session ID

    return (row == null) ? null : safeGet(row, columnKey);
  }

  @Override
  public boolean isEmpty() {
    return size() == 0;
  }

  @Override
  public void clear() {
    Iterators.clear(cellSet().iterator());
  }

  @CanIgnoreReturnValue
  @Override
  public @Nullable V remove(@Nullable Object rowKey, @Nullable Object columnKey) {
    Map<C, V> row = safeGet(rowMap(), rowKey);