assertEquals((Integer) 2, it.next());
    it.remove();
    // After this remove, 400 has moved up and 20 down past cursor
    assertTrue("Heap is not intact after remove", mmHeap.isIntact());
    assertEquals((Integer) 10, it.next());
    assertEquals((Integer) 3, it.next());
    it.remove();
    // After this remove, 400 moved down again and 500 up past the cursor

    * `200` 是默认状态代码，表示一切**正常**
    * `201` 表示**已创建**，通常在数据库中创建新记录后使用
    * `204` 是一种特殊的例子，表示**无内容**。该响应在没有为客户端返回内容时使用，因此，该响应不能包含响应体
* **`300`** 及以上的状态码用于**重定向**。具有这些状态码的响应不一定包含响应体，但 `304`**未修改**是个例外，该响应不得包含响应体
* **`400`** 及以上的状态码用于表示**客户端错误**。这些可能是第二常用的类型
    * `404`，用于**未找到**响应
    * 对于来自客户端的一般错误，可以只使用 `400`
* `500` 及以上的状态码用于表示服务器端错误。几乎永远不会直接使用这些状态码。应用代码或服务器出现问题时，会自动返回这些状态代码

/// tip | "提示"

                    <mxGeometry x="-10" y="400" width="310" height="80" as="geometry"/>
                </mxCell>

/**
 * Defines a simple logging interface for Maven CLI operations.
 * This interface provides methods for logging messages at different severity levels
 * and supports logging with or without associated exceptions.
 *
 * @since 4.0.0
 */
@Experimental
public interface Logger {

    /**
     * Represents the severity levels for log messages.
     */
    enum Level {
        DEBUG,
        INFO,
        WARN,
        ERROR

/**
 * Request used to build a {@link org.apache.maven.api.Project} using
 * the {@link ProjectBuilder} service.
 *
 * TODO: add validationLevel, activeProfileIds, inactiveProfileIds, resolveDependencies
 *
 * @since 4.0.0
 */
@Experimental
@Immutable
public interface ProjectBuilderRequest {

    @Nonnull
    Session getSession();

    @Nonnull
    Optional<Path> getPath();

    @Nonnull

    * 🎁 💼 `204`, "🙅‍♂ 🎚". 👉 📨 ⚙️ 🕐❔ 📤 🙅‍♂ 🎚 📨 👩‍💻, & 📨 🔜 🚫 ✔️ 💪.
* **`300`** & 🔛 "❎". 📨 ⏮️ 👫 👔 📟 5️⃣📆 ⚖️ 5️⃣📆 🚫 ✔️ 💪, 🌖 `304`, "🚫 🔀", ❔ 🔜 🚫 ✔️ 1️⃣.
* **`400`** & 🔛 "👩‍💻 ❌" 📨. 👫 🥈 🆎 👆 🔜 🎲 ⚙️ 🏆.
    * 🖼 `404`, "🚫 🔎" 📨.
    * 💊 ❌ ⚪️➡️ 👩‍💻, 👆 💪 ⚙️ `400`.
* `500` & 🔛 💽 ❌. 👆 🌖 🙅 ⚙️ 👫 🔗. 🕐❔ 🕳 🚶 ❌ 🍕 👆 🈸 📟, ⚖️ 💽, ⚫️ 🔜 🔁 📨 1️⃣ 👫 👔 📟.

/// tip

import org.apache.maven.api.annotations.Nonnull;
import org.apache.maven.api.annotations.NotThreadSafe;

import static org.apache.maven.api.services.BaseRequest.nonNull;

/**
 *
 *
 * @since 4.0.0
 */
@Experimental
@Immutable
public interface ArtifactFactoryRequest {

    @Nonnull
    Session getSession();

    String getGroupId();

    String getArtifactId();

    String getVersion();

/**
 * Handles normalization of a model.
 *
 * @deprecated use {@link org.apache.maven.api.services.ModelBuilder} instead
 */
@Named
@Singleton
@Deprecated(since = "4.0.0")
public class DefaultModelNormalizer implements ModelNormalizer {

    private DuplicateMerger merger = new DuplicateMerger();

    @Override
    public void mergeDuplicates(

    }

    /**
     * @see MavenExecutionRequest#getTopDirectory()
     * @since 4.0.0
     */
    public Path getTopDirectory() {
        return request.getTopDirectory();
    }

    /**
     * @see MavenExecutionRequest#getRootDirectory()
     * @since 4.0.0
     */
    public Path getRootDirectory() {
        return request.getRootDirectory();
    }

        dependency1.setArtifactId("dep1");
        Dependency dependency2 = new Dependency();
        dependency2.setArtifactId("dep2");

        project = new Project();
        project.setModelVersion("4.0.0");
        project.setGroupId("org.apache.maven");
        project.setArtifactId("maven-core");
        project.setName("Maven");
        project.setVersion("2.0-SNAPSHOT");
        project.setScm(new Scm());