title: Angular4: router, children (optional) parameters
body: <p>So, I am looking to produce paths like these:</p>
  
  <blockquote>
    <p>matches/:page/:team/:season</p>
  </blockquote>
  
  <p>where :team and :season are optional parameters
  so I could have an url like</p>
  
  <pre><code>matches/results/4/2017 or
  matches/results/4 or
  matches/results
  </code></pre>
  
  <p>all should be valid and come through in <code>this.route.snapshot.params</code></p>
  
  <p>I tried this:</p>
  
  <pre><code>  {path: 'matches', children: [
      {path: '', pathMatch: 'full', redirectTo: 'fixtures'},
      {path: 'competitions', component: CompetitionsPageComponent},
      {path: ':page', component: PageComponent, children: [
        {path: ':team', children:[
            {path: ':season', children:[]}
        ]}
      ]},
    ]},
  </code></pre>
  
  <p>with no luck, only :page comes through as param</p>