```

////

/// tip

You can set a dependency override for a dependency used anywhere in your **FastAPI** application.

The original dependency could be used in a *path operation function*, a *path operation decorator* (when you don't use the return value), a `.include_router()` call, etc.

FastAPI will still be able to override it.

///

    assertThrows(
        ConcurrentModificationException.class,
        () -> {
          Iterator<Entry<K, V>> iterator = getMap().entrySet().iterator();
          putAll(MinimalCollection.of(e3(), e0()));
          iterator.next();
        });
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)

            List<String> methods = getHeaderFields0().get(authHeader);
            if ( methods == null )
                return null;
            Iterator<String> iterator = methods.iterator();
            while ( iterator.hasNext() ) {
                String currentAuthMethod = iterator.next();
                if ( currentAuthMethod.startsWith("NTLM") ) {
                    if ( currentAuthMethod.length() == 4 ) {

///

```Python hl_lines="22"
{!> ../../docs_src/dependencies/tutorial005.py!}
```

////

/// info

Notice that we are only declaring one dependency in the *path operation function*, the `query_or_cookie_extractor`.

But **FastAPI** will know that it has to solve `query_extractor` first, to pass the results of that to `query_or_cookie_extractor` while calling it.

///

```mermaid

    public void setRootLoggerLevel(Level level) {
        LOGGER.warn("setRootLoggerLevel: operation not supported");
    }

    public void activate() {
        LOGGER.warn("activate(): operation not supported");
    }

			objectName:         objectName,
			accessKey:          "Invalid-AccessID",
			secretKey:          credentials.SecretKey,
			expectedRespStatus: http.StatusForbidden,
		},
	}

	// Iterating over the cases, fetching the object validating the response.
	for i, testCase := range testCases {
		// initialize HTTP NewRecorder, this records any mutations to response writer inside the handler.

    assertEqualInOrder(expected, multimap().values());
  }

  @CollectionFeature.Require(SUPPORTS_ITERATOR_REMOVE)
  @CollectionSize.Require(ONE)
  public void testValuesIteratorRemove() {
    Iterator<V> valuesItr = multimap().values().iterator();
    valuesItr.next();
    valuesItr.remove();
    assertTrue(multimap().isEmpty());
  }

  public void testRemove_nullKeyQueriesUnsupported() {
    try {
      assertFalse(getMap().remove(null, v3()));
    } catch (NullPointerException tolerated) {
      // since the operation would be a no-op, the exception is not required
    }
    expectUnchanged();
  }

  @MapFeature.Require(value = SUPPORTS_REMOVE, absent = ALLOWS_NULL_VALUE_QUERIES)

  public void testRemove_nullKeyQueriesUnsupported() {
    try {
      assertFalse(getMap().remove(null, v3()));
    } catch (NullPointerException tolerated) {
      // since the operation would be a no-op, the exception is not required
    }
    expectUnchanged();
  }

  @MapFeature.Require(value = SUPPORTS_REMOVE, absent = ALLOWS_NULL_VALUE_QUERIES)

    assertThrows(
        ConcurrentModificationException.class,
        () -> {
          Iterator<Entry<K, V>> iterator = getMap().entrySet().iterator();
          putAll(MinimalCollection.of(e3(), e0()));
          iterator.next();
        });
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)