title: Importing modules with forRoot()
body: <p>I am going through the <a href="https://github.com/jelbourn/material2-app/blob/master/src/app/app.module.ts" rel="noreferrer">example of Angular2 Material</a> and I see that all Material modules are imported in the root module using the <code>forRoot()</code> method. So in my app I do the same.</p>
  
  <p>Now I need to use some Material components within other Shared modules, which means that I need to import the related Material packages in my Shared module. I am not clear whether I need to use the <code>forRoot()</code> method also while importing them in the Shared module.</p>
  
  <p>Thanks in advance for any help</p>