/**
     * Gets the effective group identifier of the model.
     *
     * @return The effective group identifier of the model or an empty string if unknown, never {@code null}.
     */
    public String getGroupId() {
        return (groupId != null) ? groupId : "";
    }

    /**
     * Sets the effective group identifier of the model.
     *

				</configuration>
			</plugin>
			<plugin>
				<groupId>com.mycila</groupId>
				<artifactId>license-maven-plugin</artifactId>
			</plugin>
			<plugin>
				<groupId>net.revelc.code.formatter</groupId>
				<artifactId>formatter-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>
	<dependencies>
		<dependency>
			<groupId>org.codelibs</groupId>
			<artifactId>corelib</artifactId>

        private final String artifactId;

        private final String version;

        private final int hashCode;

        CacheKey(String groupId, String artifactId, String version) {
            this.groupId = (groupId != null) ? groupId : "";
            this.artifactId = (artifactId != null) ? artifactId : "";
            this.version = (version != null) ? version : "";

            int hash = 17;

  <artifactId>aid</artifactId>
  <groupId>gid</groupId>
  <version>0.1</version>
  <packaging>pom</packaging>

  <build>
    <pluginManagement>
      <plugins>
        <plugin>
          <groupId>test</groupId>
          <artifactId>managed-duplicate</artifactId>
        </plugin>
        <plugin>
          <groupId>test</groupId>
          <artifactId>managed-duplicate</artifactId>

      <groupId>org.apache.maven</groupId>
      <artifactId>maven-api-di</artifactId>
    </dependency>
    <dependency>
      <groupId>org.apache.maven</groupId>
      <artifactId>maven-api-model</artifactId>
    </dependency>
    <dependency>
      <groupId>org.apache.maven</groupId>
      <artifactId>maven-api-settings</artifactId>
    </dependency>
    <dependency>
      <groupId>org.apache.maven</groupId>

        if (projectGav == null || projectGav.groupId() == null) {
            return false;
        }

        // We can infer the groupId if the declared groupId matches the project groupId
        return Objects.equals(declaredGroupId, projectGav.groupId());
    }

            this.trace = trace;
            return this;
        }

        public DependencyCoordinatesFactoryRequestBuilder groupId(String groupId) {
            this.groupId = groupId;
            return this;
        }

        public DependencyCoordinatesFactoryRequestBuilder artifactId(String artifactId) {
            this.artifactId = artifactId;

<project>
  <modelVersion>4.0.0</modelVersion>
  <groupId>maven-t04</groupId>
  <artifactId>p0</artifactId>
  <packaging>pom</packaging>
  <name>p0</name>
  <version>1.0</version>
  <organization>
    <name>Codehaus</name>
  </organization>

  <dependencyManagement>

    <dependencies>

      <dependency>
        <groupId>maven-test</groupId>
        <artifactId>t04-a</artifactId>
        <version>1.0</version>

<project>
  <modelVersion>4.0.0</modelVersion>
  <groupId>maven-t09</groupId>
  <artifactId>p0</artifactId>
  <packaging>pom</packaging>
  <name>p0</name>
  <version>1.0</version>
  <organization>
    <name>Codehaus</name>
  </organization>

  <dependencyManagement>

    <dependencies>

      <dependency>
        <groupId>maven-test</groupId>
        <artifactId>t09-a</artifactId>
        <version>1.0</version>

     */
    private String getPluginKey(Plugin plugin) {
        String groupId = plugin.getGroupId();
        String artifactId = plugin.getArtifactId();

        // Default groupId for Maven plugins
        if (groupId == null && artifactId != null && artifactId.startsWith(MAVEN_PLUGIN_PREFIX)) {
            groupId = DEFAULT_MAVEN_PLUGIN_GROUP_ID;
        }