But we want to be able to parameterize that fixed content.

## A "callable" instance

In Python there's a way to make an instance of a class a "callable".

Not the class itself (which is already a callable), but an instance of that class.

To do that, we declare a method `__call__`:

{* ../../docs_src/dependencies/tutorial011_an_py39.py hl[12] *}

Here's where we are using the same OAuth2 scheme we created before, declaring it as a dependency: `oauth2_scheme`.

Because this dependency function doesn't have any scope requirements itself, we can use `Depends` with `oauth2_scheme`, we don't have to use `Security` when we don't need to specify security scopes.

We also declare a special parameter of type `SecurityScopes`, imported from `fastapi.security`.

  <artifactId>testinvalidpom</artifactId>
  <version>0.0.1-SNAPSHOT</version>

  <description>
    This will test if the module validator recognized that this
    dependency is the same as the module itself.
  </description>
  <dependencies>
    <dependency>
      <groupId>com.example.group</groupId>
      <artifactId>testinvalidpom</artifactId>
      <version>0.0.1-SNAPSHOT</version>
    </dependency>

  <artifactId>testvalidpom</artifactId>
  <version>0.0.1-SNAPSHOT</version>

  <description>
    This will test if the module validator recognized that this dependency with classifier
    is not the same as the module itself.
  </description>
  <dependencies>
    <dependency>
      <groupId>com.example.group</groupId>
      <artifactId>testvalidpom</artifactId>
      <version>0.0.1-SNAPSHOT</version>
      <classifier>linux</classifier>

/// note | "Technical Details"

Actually, `Query`, `Path` and others you'll see next create objects of subclasses of a common `Param` class, which is itself a subclass of Pydantic's `FieldInfo` class.

And Pydantic's `Field` returns an instance of `FieldInfo` as well.

 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven;

/**
 * Signals an internal error in Maven itself, e.g. a programming bug.
 *
 */
public class InternalErrorException extends MavenExecutionException {

    public InternalErrorException(String message, Throwable cause) {
        super(message, cause);
    }

import static java.util.stream.Collectors.toMap;

/**
 * Provides information about artifacts (identified by groupId:artifactId string key) and classpath elements exported by
 * Maven core itself and loaded Maven core extensions.
 *
 * @since 3.3.0
 */
public class CoreExports {
    private final Set<String> artifacts;

    private final Map<String, ClassLoader> packages;

  public abstract Iterable<T> children(T root);

  /**
   * Returns an unmodifiable iterable over the nodes in a tree structure, using pre-order traversal.
   * That is, each node's subtrees are traversed after the node itself is returned.
   *
   * <p>No guarantees are made about the behavior of the traversal when nodes change while iteration
   * is in progress or when the iterators generated by {@link #children} are advanced.
   *

      Collection<V> result = unfiltered.asMap().get(key);
      if (result == null) {
        return null;
      }
      @SuppressWarnings("unchecked") // key is equal to a K, if not a K itself
      K k = (K) key;
      result = filterCollection(result, new ValuePredicate(k));
      return result.isEmpty() ? null : result;
    }

    @Override
    @CheckForNull

 */
@Deprecated(since = "4.0.0")
public interface DependencyManagementInjector {

    /**
     * Merges default values from the dependency management section of the given model into itself.
     *
     * @param model The model into which to merge the values specified by its dependency management sections, must not
     *            be <code>null</code>.