title: Adding arguments into component throws an error
body: <p>I have a simple <code>component</code>  like this:</p>
  
  <pre><code>import { Component, Optional  } from '@angular/core';
      @Component({
        selector: 'error-handler',
        templateUrl: './error-handler.component.html',
        styleUrls: ['./error-handler.component.css']
      })
      export class ErrorHandlerComponent  {
  
          constructor(@Optional() private error?: any) { }
  
      }
  </code></pre>
  
  <p>and when I go to browser I get an error: </p>
  
  <pre><code>Uncaught Error: Can't resolve all parameters for ErrorHandlerComponent: (?).
  </code></pre>
  
  <p>I have register my new <code>component</code> in module so I don't know why this error occures. I don't call the constructor from anywhere yet.</p>
  
  <p>What is the way to provide arguments into contructor of the <code>component</code>?</p>