title: How to add a computed observable to a mapped view model?
body: <p>I'd like to simply add a computed observable to a object that is mapped.  I'd like to avoid adding a parent view model.  I've tried using the mapped options create but that doesn't seem to work.</p>
  
  <pre><code>$.getJSON(apiUrl, function (data) {
  
           var mappingOptions = {
  
            // overriding the default creation / initialization code
            create: function (options) {
  
            ko.mapping.fromJS(options.data, {}, this);
  
             // setup the computed binding
             this.FullNameComputed= ko.computed(function () {
                     return this.FirstName() + this.LastName();
                    }, this);               
              }        
            };
  
            ko.mapping.fromJS(data, mappingOptions, self.Users);
  }
  </code></pre>