Use the Unity Package Manager Client class to manage the packages used in a project.
**注意：**只能按顺序调用客户端方法。如果尝试同时添加或删除多个包，结果将具有不确定性。例如，如果在 Remove 操作正在进行或已排队时对包调用 Remove 方法，则可能覆盖当前操作，并且只处理最新的 Remove 操作。
| LogLevel | Gets or sets the log level that the Package Manager uses when logging to the Editor.log and upm.log files. Defaults to LogLevel.Info. |
| Add | Adds a package dependency to the project. Requesting a new or different dependency often leads to changing installed packages, but only after the Package Manager constructs a dependency graph to solve any version conflicts. For more information, see Dependency and resolution. |
| AddAndRemove | Adds package dependencies to the project and removes package dependencies from the project. Requesting different dependencies often leads to changing installed packages, but only after the Package Manager constructs a dependency graph to solve any version conflicts. For more information, see Dependency and resolution. Calling this function is much more efficient than calling the Add and Remove functions several times because for this function, the Package Manager only has to solve the dependency list once, instead of constructing a new dependency graph after each call. |
| ClearCache | Empties the package cache. |
| Embed | Embeds a package inside the project. |
| List | 列出项目所依赖的包。 |
| Pack | 从包文件夹中创建一个 GZip tarball 文件。该文件的格式和内容与将包发布到包注册表时的文件相同。 |
| Remove | Removes a package dependency from the project. Removing a dependency often leads to changing installed packages, but only after the Package Manager constructs a dependency graph to solve any version conflicts. For more information, see Dependency and resolution. |
| Resolve | Forces the Package Manager to resolve the project's packages, reinstalling any altered or missing package and removing extraneous packages. |
| Search | Searches for the given package. |
| SearchAll | Searches for all discoverable packages compatible with the current Unity version. |