code: public static ExtensionId toExtensionId(String groupId, String artifactId, String classifier, String version)
      {
          return toExtensionId(groupId, artifactId, classifier, version != null ? new DefaultVersion(version) : null);
      }
docs: Create a extension identifier from Maven artifact identifier elements.
  
  @param groupId the group id
  @param artifactId the artifact id
  @param classifier the classifier
  @param version the version
  @return the extension identifier
  @since 10.9
  @since 10.8.1