new_contents: from django.conf.urls import patterns, url
  from rest_framework.urlpatterns import format_suffix_patterns
  from timer import views
  
  urlpatterns = patterns('',
      url(r'^timers/$', views.TimerList.as_view()),
      url(r'^timers/(?P<pk>[0-9]+)/$', views.TimerDetail.as_view()),
  )
  
  urlpatters = format_suffix_patterns(urlpatterns)
  
subject: Add timer/urls.py