*
     * @return The model being built, never {@code null}.
     */
    Model getModel();

    /**
     * Gets the model building request being processed.
     *
     * @return The model building request being processed, never {@code null}.
     */
    ModelBuildingRequest getRequest();

    /**
     * Gets the container used to collect problems that were encountered while processing the event.

        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        // despite all are back, we need to make sure all the events are processed (are async)
        // this one should block until all processed
        listener.transferSucceeded(new TransferEvent.Builder(session, resource)
                .setType(TransferEvent.EventType.SUCCEEDED)
                .build());

@Deprecated(since = "4.0.0")
public interface ModelPathTranslator {

    /**
     * Resolves the well-known paths of the specified model against the given base directory. Paths within plugin
     * configuration are not processed.
     *
     * @param model The model whose paths should be resolved, may be {@code null}.
     * @param basedir The base directory to resolve relative paths against, may be {@code null}.

        listener.transferInitiated(event(session, resource, TransferEvent.EventType.INITIATED));

        Thread.sleep(500); // to make sure queue is processed, cancellation applied

        // subsequent call will cancel
        assertThrows(
                TransferCancelledException.class,

    ModelBuildingRequest setPomPath(Path pomPath);

    /**
     * Gets the level of validation to perform on processed models.
     *
     * @return The level of validation to perform on processed models.
     */
    int getValidationLevel();

    /**
     * Sets the level of validation to perform on processed models. For building of projects,

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

    /**
     * Notifies the listener that the model has been constructed to the extent where build extensions can be processed.
     *
     * @param event The details about the event.
     */
    void buildExtensionsAssembled(ModelBuildingEvent event);

A "middleware" is a function that works with every **request** before it is processed by any specific *path operation*. And also with every **response** before returning it.

* It takes each **request** that comes to your application.
* It can then do something to that **request** or run any needed code.
* Then it passes the **request** to be processed by the rest of the application (by some *path operation*).

     * Performs the specified bean configuration.
     *
     * @param request The configuration request that specifies the bean and the configuration to process, must not be
     *            {@code null}.
     * @throws BeanConfigurationException If the bean configuration could not be successfully processed.
     */
    void configureBean(BeanConfigurationRequest request) throws BeanConfigurationException;

     *
     * @param value The configuration value to preprocess, must not be {@code null}.
     * @param type The target type of the value, may be {@code null}.
     * @return The processed configuration value or {@code null} if none.
     * @throws BeanConfigurationException If an error occurred while preprocessing the value.
     */

 */
package org.apache.maven.model.building;

import java.util.function.Supplier;

import org.apache.maven.building.Source;

/**
 * Caches auxiliary data used during model building like already processed raw/effective models. The data in the cache
 * is meant for exclusive consumption by the model builder and is opaque to the cache implementation. The cache key is