*/
    @Nonnull
    String getExtension();

    /**
     * Get the default classifier associated to the dependency type.
     * The default classifier can be overridden when specifying
     * the {@link Dependency#getClassifier()}.
     *
     * @return the default classifier, or {@code null}.
     */
    @Nullable
    String getClassifier();

    /**

        this.groupId = (groupId != null && !groupId.isEmpty()) ? groupId : null;
        this.artifactId = (artifactId != null && !artifactId.isEmpty()) ? artifactId : null;
        this.classifier = (classifier != null && !classifier.isEmpty()) ? classifier : null;
        this.extension = (extension != null && !extension.isEmpty()) ? extension : null;
        this.version = (version != null && !version.isEmpty()) ? version : null;

        if (request.getType() != null) {
            type = session.getSession().getArtifactTypeRegistry().get(request.getType());
        }
        String str1 = request.getClassifier();
        String classifier =
                str1 != null && !str1.isEmpty() ? request.getClassifier() : type != null ? type.getClassifier() : null;
        String str = request.getExtension();
        String extension =

        a = artifactFactory.createArtifactWithClassifier("groupId", "a", "0.0.1-SNAPSHOT", "jar", "classifier");
        file = new File(localRepository.getBasedir(), localRepository.pathOf(a));
        a.setFile(file);

        assertEquals(
                "a-0.0.1-SNAPSHOT-classifier.jar.lastUpdated",
                updateCheckManager.getTouchfile(a).getName());
    }

                "sample.group",
                "sample-art",
                VersionRange.createFromVersion("1.0"),
                "scope",
                "jar",
                "classifier",
                null);
        artifact.setFile(getTestFile("target/sample-art"));

        StringWagon wagon = (StringWagon) wagonManager.getWagon("string");

        wagon.clearExpectedContent();

                        && srcInfo.repository != dstInfo.repository)) {
            infos.put(dstKey, srcInfo);
        }
    }

    private String getKey(String classifier, String extension) {
        return (classifier == null ? "" : classifier.trim()) + ':' + (extension == null ? "" : extension.trim());
    }

    private ArtifactRepository getRepository(

            metadata = metadata.withPlugins(new ArrayList<>(recessive.getPlugins()));
        }

        artifacts.clear();
    }

    private String getKey(String classifier, String extension) {
        return classifier + ':' + extension;
    }

    @Override
    public String getGroupId() {
        return metadata.getGroupId();
    }

    @Override
    public String getArtifactId() {

      <fields>
        <field>
          <name>classifier</name>
          <version>1.1.0+</version>
          <type>String</type>
          <description>The classifier of the sub-artifact. Each classifier and extension pair may only appear once.</description>
          <defaultValue></defaultValue>
          <identifier>true</identifier>

    <dependency>
      <groupId>org.eclipse.sisu</groupId>
      <artifactId>org.eclipse.sisu.inject</artifactId>
      <classifier>no_asm</classifier>
    </dependency>
    <dependency>
      <groupId>com.google.inject</groupId>
      <artifactId>guice</artifactId>
      <classifier>classes</classifier>
    </dependency>
    <dependency>
      <groupId>org.ow2.asm</groupId>
      <artifactId>asm</artifactId>

    @Override
    public ArtifactCoordinate createArtifactCoordinate(
            String groupId, String artifactId, String version, String classifier, String extension, String type) {
        return getService(ArtifactCoordinateFactory.class)
                .create(this, groupId, artifactId, version, classifier, extension, type);
    }

    /**
     * Shortcut for <code>getService(CoordinateFactory.class).create(...)</code>
     *