which might be interesting to read and for further discussion.

Getting Started
---------------

+ Make sure you have a [JIRA account](https://issues.apache.org/jira/).
+ Make sure you have a [GitHub account](https://github.com/signup/free).
+ If you're planning to implement a new feature, it makes sense to discuss your changes
  on the [dev list](https://maven.apache.org/mailing-lists.html) first.

import java.util.List;

import org.apache.maven.api.model.InputLocation;

/**
 * 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

        }

        return pluginManager.getMojoDescriptor(
                plugin, goal, project.getRemotePluginRepositories(), session.getRepositorySession());
    }

    // TODO take repo mans into account as one may be aggregating prefixes of many
    // TODO collect at the root of the repository, read the one at the root, and fetch remote if something is missing
    // or the user forces the issue

import org.apache.maven.artifact.repository.ArtifactRepository;
import org.apache.maven.artifact.versioning.OverConstrainedVersionException;

/**
 * Specific problems during resolution that we want to account for:
 * <ul>
 *   <li>missing metadata</li>
 *   <li>version range violations</li>
 *   <li>version circular dependencies</li>
 *   <li>missing artifacts</li>
 *   <li>network/transfer errors</li>

    // In this case, both the verify and the report goals are called
    // in a different lifecycle. Though the compiler-plugin has a valid use case, although
    // that seems to work fine. We need to take versions and lifecycle into account.
    public ProjectSorter(Collection<MavenProject> projects) throws CycleDetectedException, DuplicateProjectException {
        graph = new Graph();

        // groupId:artifactId:version -> project

import org.apache.maven.api.services.ModelProblemCollector;
import org.apache.maven.api.spi.ModelParserException;

/**
 * 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

    // 5) Execute AbstractLifecycleParticipant.afterSessionStart(session)
    //
    // 6) Get reactor projects looking for general POM errors
    //
    // 7) Create ProjectDependencyGraph using trimming which takes into account --projects and reactor mode.
    // This ensures that the projects passed into the ReactorReader are only those specified.
    //

            return value == null || value.isEmpty();
        }

        /**
         * Returns a comparable value for a qualifier.
         * <p>
         * This method takes into account the ordering of known qualifiers then unknown qualifiers with lexical
         * ordering.
         * <p>
         *
         * @param qualifier

          <version>4.0.0+</version>
          <description>
            Indicates the dependency is optional for use of this library. While the
            version of the dependency will be taken into account for dependency calculation if the
            library is used elsewhere, it will not be passed on transitively. Note: While the type
            of this field is {@code String} for technical reasons, the semantic type is actually

- plugin in any default values
- check to see if anything is missing