constant is included for completeness.
 *  New: Upgrade to Okio 1.14.0.

     ```xml
     <dependency>
       <groupId>com.squareup.okio</groupId>
       <artifactId>okio</artifactId>
       <version>1.14.0</version>
     </dependency>

     com.squareup.okio:okio:1.14.0
     ```

 *  Fix: Handle `HTTP/1.1 100 Continue` status lines, even on requests that did

public interface ModelResolver {

    /**
     * Tries to resolve the POM for the specified coordinates.
     *
     * @param groupId The group identifier of the POM, must not be {@code null}.
     * @param artifactId The artifact identifier of the POM, must not be {@code null}.
     * @param version The version of the POM, must not be {@code null}.
     * @return The source of the requested POM, never {@code null}.

        // make sure to call the subclasses' builder methods first, otherwise fluent API would not work
        builder.additionalField("additional")
                .groupId("org.apache.maven")
                .artifactId("maven-plugin-api")
                .version("1.0.0");
        ExtendedPluginDescriptor descriptor = builder.build();
        assertEquals("additional", descriptor.getAdditionalField());

  </properties>

  <build>
    <directory>${project.basedir}/target</directory>
    <outputDirectory>${project.build.directory}/classes</outputDirectory>
    <finalName>${project.artifactId}-${project.version}</finalName>
    <testOutputDirectory>${project.build.directory}/test-classes</testOutputDirectory>
    <sourceDirectory>${project.basedir}/src/main/java</sourceDirectory>

     *
     * @return the location
     */
    public String getLocation() {
        return this.location;
    }

    /**
     * Get the identifier of the POM in the format {@code <groupId>:<artifactId>:<version>}.
     *
     * @return the model id
     */
    public String getModelId() {
        return this.modelId;
    }

    /**

 * @since 4.0.0
 */
@Experimental
public interface ProjectBuilderResult {

    /**
     * Gets the identifier of the project that could not be built. The general format of the identifier is {@code
     * <groupId>:<artifactId>:<version>} but some of these coordinates may still be unknown at the point the exception
     * is thrown so this information is merely meant to assist the user.
     *

        return result;
    }

    /**
     * Gets the identifier of the POM whose effective model could not be built. The general format of the identifier is
     * {@code <groupId>:<artifactId>:<version>} but some of these coordinates may still be unknown at the point the
     * exception is thrown so this information is merely meant to assist the user.
     *

  </properties>

  <build>
    <directory>${project.basedir}/target</directory>
    <outputDirectory>${project.build.directory}/classes</outputDirectory>
    <finalName>${project.artifactId}-${project.version}</finalName>
    <testOutputDirectory>${project.build.directory}/test-classes</testOutputDirectory>
    <sourceDirectory>${project.basedir}/src/main/java</sourceDirectory>

            throw new MetadataResolutionException(
                    "treenode without metadata, parent: " + (parent == null ? "null" : parent.toString()));
        }

        return md.groupId + ":" + md.artifactId;
    }

    // ------------------------------------------------------------------------
    public boolean hasChildren() {
        return children != null;
    }

 * followed by <dfn>flattening</dfn> and <dfn>resolution</dfn>.
 * The version selection is done for each dependency during the collection phase.
 * The flatten phase will keep only a single version per ({@code groupId}, {@code artifactId}) pair.
 * The resolution will actually download the dependencies (or artifacts) that have been computed.
 *
 * @since 4.0.0
 */
@Experimental
@Immutable
public interface Dependency extends Artifact {
    /**