title: How to use Nest.js's @Headers properly?
body: <p>According to the <a href="https://docs.nestjs.com/controllers" rel="noreferrer">controller docs</a> I can use <code>@Headers(param?: string)</code> or <code>req.headers</code> or <code>req.headers[param]</code> to get header value. I tried the first approach, I have following in my request headers from Postman</p>
  
  <pre><code>Content-Type:application/json
  My-Id:test12345
  </code></pre>
  
  <p>I have following controller sample code</p>
  
  <pre><code>@Put('/aa/:aa/bb/:bb/')
  @UsePipes(new ValidationPipe({ transform: true }))
  public async DoMyJob(@Body() request: MyRequestDto,
                                  @Param('aa') aa: number,
                                  @Param('bb') bb: string,
                                  @Headers('My-Id') id: string): Promise&lt;MyResponseDto&gt; {
      // More code here
  }
  </code></pre>
  
  <p>When I set break point to inspect the value from <code>My-Id</code> header it is undefined.</p>
  
  <p>So how shall I do in Nest.Js properly to get the header value from RESTful service client?</p>