project
- nice little sample projects that could be run in the core as well as integration tests

All Possible Errors
- invalid lifecycle phase (maybe same as bad CLI param, though you were talking about embedder too)
- <module> specified is not found
- malformed settings
- malformed POM
- local repository not writable
- remote repositories not available
- artifact metadata missing
- extension metadata missing

     */
    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);

    /**
     *

        }
        msg += ")";
        logger.debug(msg);
    }

    public void manageArtifactVersion(Artifact artifact, Artifact replacement) {
        // only show msg if a change is actually taking place
        if (!replacement.getVersion().equals(artifact.getVersion())) {
            String msg = indent + artifact + " (applying version: " + replacement.getVersion() + ")";
            logger.debug(msg);
        }

/**
 * Collects problems that are encountered during model building. The primary purpose of this component is to account for
 * the fact that the problem reporter has/should not have information about the calling context and hence cannot provide
 * an expressive source hint for the model problem. Instead, the source hint is configured by the model builder before

        // We have metadata retrieval problems, or there are cycles that have been detected
        // so we give this back to the calling code and let them deal with this information
        // appropriately.

        if (result.hasMetadataResolutionExceptions()
                || result.hasVersionRangeViolations()

        // explicit child override depMgmt (viz. depMgmt should only
        // provide defaults to children, but should override transitives).
        // We can do this by calling isChildOfRootNode on the current node.
        if ((artifact.getVersion() != null)
                && (!node.isChildOfRootNode() || node.getArtifact().getVersion() == null)) {

import org.apache.maven.api.annotations.Nullable;

import static org.apache.maven.api.services.BaseRequest.nonNull;

/**
 * Provides access to the contents of a source independently of the
 * backing store (e.g. file system, database, memory).
 * <p>
 * This is mainly used to parse files into objects such as
 * {@link org.apache.maven.api.Project},
 * {@link org.apache.maven.api.model.Model},

/**
 * Collects problems that are encountered during model building. The primary purpose of this component is to account for
 * the fact that the problem reporter has/should not have information about the calling context and hence cannot provide
 * an expressive source hint for the model problem. Instead, the source hint is configured by the model builder before

        return getPackaging().language();
    }

    /**
     * Returns the project POM artifact, which is the artifact of the POM of this project. Every project have a POM
     * artifact, even if the existence of backing POM file is NOT a requirement (i.e. for some transient projects).
     *
     * @see org.apache.maven.api.services.ArtifactManager#getPath(Artifact)
     */
    @Nonnull
    default Artifact getPomArtifact() {

 * under the License.
 */
package org.apache.maven.building;

import java.io.IOException;
import java.io.InputStream;

/**
 * Provides access to the contents of a source independently of the backing store (e.g. file system, database, memory).
 *
 */
public interface Source {

    /**
     * Gets a byte stream to the source contents. Closing the returned stream is the responsibility of the caller.
     *