text: from unittest import TestCase
  import filehandling
  
  
  class TestOpen(TestCase):
      def test_open_filename(self):
          file = filehandling.open_filename()
          self.assertTrue(type(file) == str)
  
  
  class TestSave(TestCase):
      def test_save_filename(self):
          file = filehandling.save_filename()
          self.assertTrue(type(file) == str)
          self.assertTrue(len(file) > 0)
  
  
  class TestOpenDirectory(TestCase):
      def test_open(self):
          direc = filehandling.open_directory()
          self.assertTrue(type(direc) == str)
  
  class TestOpenFileNames(TestCase):
      def test(self):
          files = filehandling.get_filenames()