anchor.diff:  var ServerCity = React.createClass({
     render: function() {
       var city = this.props.city;
  -    if (!city) {
  -      city = "unknown location";
  -    }
       return (
  -      <span className="serverCity">{city}</span>
  +      <span className="serverCity"><tt>{city}</tt></span>
       );
     }
   });
  
positive.code:         var newState = {};
          newState[propPrefix + "Id"] = data.id;
          newState[propPrefix + "City"] = data.city;
          this.setState(newState);
          if (!data.city) { // retry until we get the city
            setTimeout(this.loadLocation, this.interval, path, propPrefix);
          }
        }.bind(this),
        error: function(xhr, status, err) {
          console.error(status, err.toString());
        }
      });
    },
  
    getInitialState: function() {
      return {};
    },
    componentDidMount: function() {
      this.loadLocation("/locations/current", "client");
  
negative.code:       buttonValue: ping.pingButton,
        buttonDisabled: false,
        resultValue: "",
        progressValue: "",
        error: null
      };
    },
    handleSubmit: function(e) {
  