mat-nav-bar missing example for method updateActiveLinks

https://github.com/angular/material2/blob/a6c6a58cc4bccddeb87ad71b33a849527e23c462/src/lib/tabs/tab-nav-bar/tab-nav-bar.ts#L118-L123

The [docs](https://material.angular.io/components/tabs/api#MatTabNav) do not provide any explanation of how to access this method. Tried checking other methods that I have used but nothing works.

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Is this this correct?
`@ViewChild( 'tabs' ) tabs: MatTabNav;`
Even tried this:
`@ViewChild( 'MatTabNav' ) tabs: MatTabNav;`

I feel like I am missing something important
`this.whatshouldthisbe.updateActiveLink( '#tabs' )`

As a side note, many other times I feel the source code makes far more sense than the docs do. Do I need to fully understand the source in order to make sense of the docs?

Start with the linked tab-nav-bar.ts source around lines 118-123 and the MatTabNav API documentation. Verify how the reported updateActiveLink/updateActiveLinks method is accessed from the shown template, then update the docs with an explanation and working example; done means newcomers can follow the example without guessing the ViewChild reference.

Written by the indexing model from the issue text.