* {@code <groupId>:<artifactId>[:<extension>[:<classifier>]]:<version>}.
     * <p>
     * Shortcut for {@code getService(ArtifactFactory.class).create(...)}.
     *
     * @param coordString the string having "standard" coordinate.
     * @return coordinate used to point to the artifact
     *
     * @see org.apache.maven.api.services.ArtifactCoordinateFactory#create(Session, String)
     */
    @Nonnull

        <field>
          <name>executions</name>
          <version>4.0.0+</version>
          <description>Multiple specifications of a set of goals to execute during the build
            lifecycle, each having (possibly) a different configuration.</description>
          <association>
            <type>PluginExecution</type>
            <multiplicity>*</multiplicity>
          </association>
        </field>

  OTOH, all offline-mode checks can probably be run from Wagon-based APIs.

** Maven-SCM

  In all but trivial examples, SCM operations cannot complete without
  having access to the versioning server. Therefore, it is assumed that
  any SCM-related activity will be unavailable when m2 is in offline
  mode.

** Maven-Core

        // snapshot timestamp, or some other timestamp later encoded into the metadata.
        // TODO this needs to be repeated here so the merging doesn't interfere with the written metadata
        //  - we'd be much better having a pristine input, and an ongoing metadata for merging instead

        Map<ArtifactRepository, Metadata> previousMetadata = new HashMap<>();
        ArtifactRepository selected = null;