Plugin plugin = Plugin.newInstance(false);
                        plugin = mergePlugin(plugin, element, sourceDominant, context);

                        Object key = getPluginKey().apply(plugin);

                        master.put(key, plugin);
                    }
                }

                Map<Object, List<Plugin>> predecessors = new LinkedHashMap<>();

      <version>1.0</version>
    </dependency>
  </dependencies>
  <build>
    <plugins>
      <plugin>
        <artifactId>maven-antrun-plugin</artifactId>
        <configuration>
          <tasks><echo>${project.parent.basedir}</echo></tasks>
        </configuration>
      </plugin>
    </plugins>
  </build>

  </scm>
  <build>
    <plugins>
      <plugin>
        <artifactId>maven-compiler-plugin</artifactId>
        <executions>
          <execution>
            <id>test</id>
            <phase>package</phase>
            <goals>
              <goal>compile</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>

 2016-05-29
 -----

Maven Compat

 Maven2 classes maintained as compatibility layer for plugins that need to keep Maven2 compatibility.

 Plugins should avoid these classes and be updated to use only Maven3 dependencies (and require Maven3): see
 {{{https://cwiki.apache.org/confluence/display/MAVEN/Plugin+migration+to+Maven3+dependencies} Plugin migration to Maven3 dependencies}}

    <dependency>
      <groupId>org.apache.maven</groupId>
      <artifactId>maven-api-xml</artifactId>
    </dependency>
  </dependencies>

  <build>
    <plugins>
      <plugin>
        <groupId>org.codehaus.modello</groupId>
        <artifactId>modello-maven-plugin</artifactId>
        <executions>
          <execution>
            <id>velocity</id>
            <goals>
              <goal>velocity</goal>
            </goals>

For external plugins, it's difficult for an object to be used outside the application of a plugin, so following best practices is relatively straightforward.  For core plugins in gradle/gradle, it's easy for an object to be created without applying its associated plugin. For instance, Spring has a plugin that uses the Checkstyle task directly without applying the Checkstyle plugin.

// See the License for the specific language governing permissions and
// limitations under the License.

// This tests the k8s installation.  It validates the CNI plugin configuration
// and the existence of the CNI plugin binary locations.
package install_test

import (
	"testing"

	install "istio.io/istio/cni/test"
	"istio.io/istio/pkg/test/env"
)

type testCase struct {

    <configuration>
      <![CDATA[
<build>
  <plugins>
    ...
  </plugins>
</build>
    ]]></configuration>
    <description>
      <![CDATA[
      This is the list of Artifact instances for plugins used in the current build
      for this project.

      NOTE: This list may contain plugin Artifacts which are implied by the current POM's

 []

 A plugin is described in a {{{./plugin.html}<<<META-INF/maven/plugin.xml>>> plugin descriptor}},
 generally generated from plugin sources using {{{/plugin-tools/maven-plugin-plugin/}maven-plugin-plugin}}.

* See Also

 * {{{/developers/mojo-api-specification.html}Mojo API Specification}}

            </excludes>
          </configuration>
        </plugin>
      </plugins>
    </pluginManagement>
    <plugins>
      <plugin>
        <groupId>org.eclipse.sisu</groupId>
        <artifactId>sisu-maven-plugin</artifactId>
      </plugin>
      <plugin>
        <groupId>org.codehaus.modello</groupId>
        <artifactId>modello-maven-plugin</artifactId>
        <configuration>