* <p>
     * Effective properties are computed from system, user and optionally project properties, layered with
     * defined precedence onto each other to achieve proper precedence. Precedence is defined as:
     * <ul>
     *     <li>System properties (lowest precedence)</li>
     *     <li>Project properties (optional)</li>
     *     <li>User properties (highest precedence)</li>

     * configuration expansion (merging configuration defined globally for a given plugin
     * using {@link org.apache.maven.api.model.Plugin#getConfiguration()}
     * into the configuration for each {@link org.apache.maven.api.model.PluginExecution}.
     */
    boolean isProcessPlugins();

    /**
     * Defines external profiles that may be activated for the given model.

            // all the tasks, then the thread will block waiting for all
            // those subtasks to finish.
            // This ensures the number of running workers is no more than
            // the defined parallism, while making sure the pool will not
            // be exhausted
            //
            return new ThreadPoolExecutor(

                        Version.V20,
                        prefix + prefix2 + "(groupId:artifactId)",
                        null,
                        "groupId of a plugin must be defined. ",
                        plugin);
            }

            if (plugin.getArtifactId() == null
                    || (plugin.getArtifactId() != null