*
 */
public interface MetadataReader {

    /**
     * The key for the option to enable strict parsing. This option is of type {@link Boolean} and defaults to {@code
     * true}. If {@code false}, unknown elements will be ignored instead of causing a failure.
     */
    String IS_STRICT = "org.apache.maven.artifact.repository.metadata.io.isStrict";

    /**
     * Reads the metadata from the specified file.
     *

     * the bean class will be used.
     *
     * @return The class loader to load referenced types from or {@code null} if unset.
     */
    ClassLoader getClassLoader();

    /**
     * Sets the class loader from which to load any types referenced by the configuration. If unset, the class loader of
     * the bean class will be used.
     *

// TODO project dependencies that need downloading
// TODO unfortunately the plugins need to be downloaded in order to get the plugin.xml file. need to externalize this
//      from the plugin archive.
// TODO this will be the class that people get in IDEs to modify

/**
 * MavenExecutionPlan
 */
public class MavenExecutionPlan implements Iterable<ExecutionPlanItem> {

    /*

if exist "%USERPROFILE%\mavenrc_post.bat" echo Warning: The mavenrc_post.bat script is deprecated and will be removed in a future version. >&2
if exist "%USERPROFILE%\mavenrc_post.bat" call "%USERPROFILE%\mavenrc_post.bat"
if exist "%USERPROFILE%\mavenrc_post.cmd" echo Warning: The mavenrc_post.cmd script is deprecated and will be removed in a future version. >&2
if exist "%USERPROFILE%\mavenrc_post.cmd" call "%USERPROFILE%\mavenrc_post.cmd"

        is the location of a file that needs to exist, and if it doesn't, the profile will be
        activated. On the other hand, {@code exists} will test for the existence of the file and if it is
        there, the profile will be activated.
        <p>Variable interpolation for these file specifications is limited to {@code ${project.basedir}},

     */
    void add(Problem.Severity severity, String message, int line, int column, Exception cause);

    /**
     * The next messages will be bound to this source. When calling this method again, previous messages keep
     * their source, but the next messages will use the new source.
     *
     * @param source a source
     */
    void setSource(String source);

    /**
     *

/**
 * The DependencyCollector service can be used to collect dependencies
 * for a given artifact and builds a graph of them.
 * The dependencies collection mechanism will not download any artifacts,
 * and only the pom files will be downloaded.
 *
 * @since 4.0.0
 */
@Experimental
public interface DependencyCollector extends Service {

    /**

 * probably roll its own.
 * <p>
 * This implementation is backed by Maven Resolver API, supported protocols and transport selection depends on it. If
 * resolver preference regarding transport is altered, it will affect this service as well.
 *
 * @since 4.0.0
 */
@Experimental
@Consumer
public interface TransportProvider extends Service {
    /**

    filesystem, it will continue to be available.

  The question remaining is: Which level of offline mode will we support? It
  seems reasonable to assume that users will be able to tell when localhost is
  not active (in most cases, localhost should be available, even if the rest of
  the network is not). Therefore, let's concentrate on the state where no
  network <beyond localhost> exists, and leave the more extreme state to users

    /**
     * Aggregating mojo executions (possibly) modify all MavenProjects, including those that are currently in use
     * by concurrently running mojo executions. To prevent race conditions, an aggregating execution will block
     * all other executions until finished.
     * We also lock on a given project to forbid a forked lifecycle to be executed concurrently with the project.