code: def check_ok(self):
          
          import requests
  
          if not self.env.check_ok:
              return
  
          # Find current git branch.
          branch_name = self._local('git rev-parse --abbrev-ref HEAD', capture=True).strip()
  
          check_ok_paths = self.env.check_ok_paths or {}
  
          if branch_name in check_ok_paths:
              check = check_ok_paths[branch_name]
              if 'username' in check:
                  auth = (check['username'], check['password'])
              else:
                  auth = None
              ret = requests.get(check['url'], auth=auth)
              passed = check['text'] in ret.content
              assert passed, 'Check failed: %s' % check['url']
docs: Ensures all tests have passed for this branch.
  
          This should be called before deployment, to prevent accidental deployment of code
          that hasn't passed automated testing.