title: Knockout Mapping Plugin - how to add properties to the default mapping?
body: <p>I originally had a viewModel like this: </p>
  
  <pre><code>var ObjectViewModel = function (data) {
      var self = this;
      //debugger;
      self.id = data.id;
      self.details = data.details;
      self.children = ko.observableArray(data.children);
  
      self.deleteChild = function (child) {
          // Pending UI
          // call API here
          // On success, complete
          self.children.remove(child);
      }.bind(self);
  
  };
  </code></pre>
  
  <p>Now I'm trying to use the mapping plugin so I can make the children array elements observables.  I've done this: </p>
  
  <pre><code>var ObjectViewModel = ko.mapping.fromJS(data);
  </code></pre>
  
  <p>But I'm not sure how to add the deleteChild method to this.</p>