old_contents: """Test mixins."""
  
  import os
  import sys
  
  import six
  
  from django.core.management import call_command
  
  
  class CallCommandMixin(object):
      """A mixin to provide command execution shortcuts."""
  
      def setUp(self):
          """Replace stdin"""
          super(CallCommandMixin, self).setUp()
          self.stdin = sys.stdin
  
      def tearDown(self):
          sys.stdin = self.stdin
  
      def import_report(self, path):
          """Import test report from file."""
          with open(path) as fp:
              buf = six.StringIO(fp.read())
          sys.stdin = buf
          call_command("import_aggregated_report", "--pipe")
  
      def import_reports(self, folder="reports"):
          """Import reports from folder."""
          path = os.path.join(os.path.dirname(__file__), folder)
          for f in os.listdir(path):
              fpath = os.path.join(path, f)
              if f.startswith(".") or not os.path.isfile(fpath):
                  continue
              self.import_report(fpath)
  
      def import_fail_reports(self, folder="fail-reports"):
          """Import failed reports from folder."""
          path = os.path.join(os.path.dirname(__file__), folder)
          for f in os.listdir(path):
              fpath = os.path.join(path, f)
              if f.startswith(".") or not os.path.isfile(fpath):
                  continue
              self.import_report(fpath)
              # TODO check return code different from 0
  
new_contents: """Test mixins."""
  
  import os
  import sys
  
  import six
  
  from django.core.management import call_command
  from django.utils.six import StringIO
  
  
  class CallCommandMixin(object):
      """A mixin to provide command execution shortcuts."""
  
      def setUp(self):
          """Replace stdin"""
          super(CallCommandMixin, self).setUp()
          self.stdin = sys.stdin
  
      def tearDown(self):
          sys.stdin = self.stdin
  
      def import_report(self, path):
          """Import test report from file."""
          with open(path) as fp:
              buf = six.StringIO(fp.read())
          sys.stdin = buf
          out = StringIO()
          call_command("import_aggregated_report", "--pipe", stdout=out)
          return out.getvalue()
  
      def import_reports(self, folder="reports"):
          """Import reports from folder."""
          path = os.path.join(os.path.dirname(__file__), folder)
          for f in os.listdir(path):
              fpath = os.path.join(path, f)
              if f.startswith(".") or not os.path.isfile(fpath):
                  continue
              self.import_report(fpath)
  
      def import_fail_reports(self, folder="fail-reports"):
          """Import failed reports from folder."""
          path = os.path.join(os.path.dirname(__file__), folder)
          for f in os.listdir(path):
              fpath = os.path.join(path, f)
              if f.startswith(".") or not os.path.isfile(fpath):
                  continue
              ret = self.import_report(fpath)
              self.assertNotIn('ERROR-PARSING', ret)
  
subject: Check if error available on output