old_contents: from subprocess import call, check_output
  
  class TestOs:
      """ Contains test methods to test 
      if the vagrant OS got installed properly """
  
  
new_contents: from subprocess import call, check_output
  
  class TestOs:
      """ Contains test methods to test 
      if the vagrant OS got installed properly """
      
      def uname_kernel(self):
          """ returns output of uname -s """
          output = check_output(["uname", "-s"]).decode("utf-8").lstrip().rstrip()
          return output
      
      def uname_os(self):
          """ returns the output of uname -o """
          output = check_output(["uname", "-o"]).decode("utf-8").lstrip().rstrip()
          return output
      
      def test_uname_kernel(self):
          """ tests the output of uname_kernel() """
          assert self.uname_kernel() == "Linux"
      
      def test_uname_os(self):
          """ tests the output of uname_os() """
          assert self.uname_os() == "GNU/Linux"
  
  
subject: Add tests for vagrant guest OS