code: function( callback, shot ) {
  
          var scope = this;
  
          switch( scope.opts.callbackReturn ) {
  
              case Webcam.CallbackReturnTypes.location:
  
                  return callback( null, shot.location );
  
  
              case Webcam.CallbackReturnTypes.buffer:
  
                  return scope.getShotBuffer( shot, callback );
  
  
              case Webcam.CallbackReturnTypes.base64:
  
                  return scope.getBase64( shot, callback );
  
              default:
  
                  return callback(
                      new Error(
                          "Callback return type not valid " + scope.opts.callbackReturn
                      )
                  );
  
          }
  
      }
docs: Get last shot taken image data
  
  @method handleCallbackReturnType
  
  @param {Function} callback
  @param {String} location
  
  @throws Error callbackReturn Type not valid