anchor.diff:  #testbed-methods
   :marked
     The `TestBed` API consists of static class methods that either update or reference a _global_ instance of the`TestBed`.
  +
  +  `TestBed`的API包含了一系列静态类方法，它们更新或者引用**全局**的`TestBed`实例。
     
     Internally, all static methods cover methods of the current runtime `TestBed` instance that is also returned by the `getTestBed()` function.
   
  +  在内部，所有静态方法在`getTestBed()`函数返回的当前运行时间的`TestBed`实例上都有对应的方法。
  +
     Call `TestBed` methods _within_ a `BeforeEach()` to ensure a fresh start before each individual test.
   
  +  在`BeforeEach()`内调用`TestBed`方法，这样确保在运行每个单独测试时，都有崭新的开始。
  +
     Here are the most important static methods, in order of likely utility.
  +
  +  这里列出了最重要的静态方法，以使用频率排序：
   table
     tr
  -    th Methods
  -    th Description
  +    th 
  +      :marked
  +        Methods
  +
  +        方法
  +    th 
  +      :marked
  +        Description
  +
  +        描述
     tr
       td(style="vertical-align: top") <code>configureTestingModule</code>
       td
  
positive.code:         Replace metadata for the given `NgModule`. Recall that modules can import other modules.
          The `overrideModule` method can reach deeply into the current testing module to
          modify one of these inner modules.
    tr
      td(style="vertical-align: top") <code>overrideComponent</code>
      td
        :marked
          Replace metadata for the given component class which could be nested deeply 
          within an inner module.
    tr
      td(style="vertical-align: top") <code>overrideDirective</code>
      td
        :marked
          Replace metadata for the given directive class which could be nested deeply 
          within an inner module.
    tr
      td(style="vertical-align: top") <code>overridePipe</code>
      td
        :marked
          Replace metadata for the given pipe class which could be nested deeply 
          within an inner module.
    tr
      td(style="vertical-align: top").
        <a id="testbed-get"></a>
  
negative.code:       :marked
          Initialize the testing environment for the entire test run.
  
          为整套测试的运行初始化测试环境。
  
          The testing shims (`karma-test-shim`, `browser-test-shim`) call it for you
          so there is rarely a reason for you to call it yourself.
  
          测试垫片(`karma-test-shim`, `browser-test-shim`)会为你调用它，所以你很少需要自己调用它。
  
          This method may be called _exactly once_. Call `resetTestEnvironment` first
          if you absolutely need to change this default in the middle of your test run.
  
          这个方法只能被调用**一次**。如果确实需要在测试运行期间变换这个默认设置，那么先调用`resetTestEnvironment`。
  
          Specify the Angular compiler factory, a `PlatformRef`, and a default Angular testing module.
          Alternatives for non-browser platforms are available in the general form
          `@angular/platform-<platform_name>/testing/<platform_name>`.
  
          指定Angular编译器工厂，`PlatformRef`，和默认Angular测试模块。
          非浏览器平台的替代以`@angular/platform-<platform_name>/testing/<platform_name>`的形式提供。
    tr
      td(style="vertical-align: top") <code>resetTestEnvironment</code>
      td
        :marked
          Reset the initial test environment including the default testing module.
  
          重设初始测试环境，包括默认测试模块在内。
  
  :marked
    A few of the `TestBed` instance methods are not covered by static `TestBed` _class_ methods.
  