def identify(identity)
      unless @session[:km_identity] == identity
        queue.delete_if { |e| e.first == 'identify' }
        queue << ['identify', identity]
        @session[:km_identity] = identity
      end
    end
def identify(identity)
      unless @session[:km_identity] == identity
        queue.delete_if { |e| e.first == 'identify' }
        queue << ['identify', identity]
        @session[:km_identity] = identity
      end
    end
The equivalent of the `KM.identify` method of the JavaScript API.