new_contents: import os
  
  
  class NullStdoutMixin(object):
      def __init__(self, *args, **kwargs):
          self._devnull = open(os.devnull, 'w')
          super(NullStdoutMixin, self).__init__(*args, **kwargs)
  
      def cleanup(self):
          if hasattr(self, '_devnull'):
              self._devnull.close()
          super(NullStdoutMixin, self).cleanup()
  
      def get_compile_popen_kwargs(self):
          result = super(NullStdoutMixin, self).get_compile_popen_kwargs()
          result['stdout'] = self.devnull
          return result
  
subject: Convert stdout redirection magic to a mixin.