old_contents: # -*- coding: utf-8 -*-
  import pytest
  
  
  class TestMarkers:
  
      @pytest.fixture
      def testdir(self, testdir):
          testdir.makeconftest("""
              pytest_plugins = 'pytest_testdox.plugin'
          """)
          return testdir
  
      def test_should_not_raise_warning_without_plugin_call(self, testdir):
          testdir.makepyfile("""
              import pytest
              
              @pytest.mark.it('Should not raise warning')
              def test_with_plugin_mark():
                  assert True
          """)
  
          result = testdir.runpytest()
  
          unknown_mark_warning = 'PytestUnknownMarkWarning'
  
          assert unknown_mark_warning not in result.stdout.str()
          assert '1 passed' in result.stdout.str()
  
new_contents: # -*- coding: utf-8 -*-
  import pytest
  
  
  class TestMarkers:
  
      @pytest.fixture
      def testdir(self, testdir):
          testdir.makeconftest("""
              pytest_plugins = 'pytest_testdox.plugin'
          """)
          return testdir
  
      def test_should_not_raise_warning_without_plugin_call(self, testdir):
          testdir.makepyfile("""
              import pytest
  
              @pytest.mark.it('Should not raise warning')
              def test_with_plugin_mark():
                  assert True
          """)
  
          result = testdir.runpytest()
  
          unknown_mark_warning = 'PytestUnknownMarkWarning'
  
          assert unknown_mark_warning not in result.stdout.str()
          assert '1 passed' in result.stdout.str()
  
subject: remove whitespaces from blank line