anchor.diff:    bootstrap(PowerBooster);
   
   :markdown
  -  Two things to note here:
  +  Two things to note:
     1. We use the pipe in the template expression exactly as we described in the pipe's comments. 
     We pass the value to transform from the left and give our pipe an exponent parameter of `10`.
     
  
positive.code:   A pipe may accept any number of optional parameters to fine-tune its output.
      
    We add parameters to a pipe by following the pipe name with a colon ( : ) and then the parameter value
    (e.g., `maxSize:1`). If our pipe accepts multiple parameters, we separate the values with colons (e.g. `between:1:5`)
    
    Let's modify our birthday example to give the date pipe a format parameter.
    The formatted date will display as **<span style="font-family:courier">04/15/88</span>**.
  
  code-example(format="linenums" escape="html").
    <p>The hero's birthday is {{ birthday | date:"MM/dd/yy" }} </p>
  
negative.code:   :markdown
      Angular reports an error if we neglect to list our custom pipe. 
      We didn't list the `DatePipe` in our previous example because all
      Angular built-in pipes are pre-registered. 
      Custom pipes must be registered manually.
  :markdown
    If we are inclined to try this in a live-coding tool (such a [plunker](http://plnkr.co/)),
  