code: def test_upload_download(self):
      folder_name = "/test_folder3"
      file_name1 = "test_file2.txt"
      file_name2 = "test_file3.txt"
      file_path = folder_name + "/" + file_name1
  
      file_descriptor = open(file_name1, "w+")
      content_file1 = (
          "Hello World! Hello PyClustering! Hello PyClustering!"
      )
      file_descriptor.write(content_file1)
      file_descriptor.close()
  
      self.assertTrue(self.__disk_client.create_folder(folder_name))
      self.assertFalse(self.__disk_client.file_exist(file_path))
  
      self.assertTrue(self.__disk_client.upload(file_name1, file_path))
      self.assertTrue(self.__disk_client.file_exist(file_path))
  
      self.assertTrue(
          self.__disk_client.download(file_path, file_name2)
      )
      self.assertTrue(os.path.isfile(file_name2))
  
      file_descriptor = open(file_name2, "r")
      content_file2 = file_descriptor.read()
      file_descriptor.close()
  
      self.assertEqual(content_file1, content_file2)
  
      self.assertTrue(self.__disk_client.delete(folder_name))
      os.remove(file_name1)
      os.remove(file_name2)
  
file_path: pyclustering/ci/cloud/tests/test_cloud.py
imports: import os
  import unittest
  from cloud.task import task
  from cloud.task_handler import task_handler
  from cloud.yandex_disk import yandex_disk
label_desc: Use image node_id 6 for calling the cloud_unit_test obj's underlying member method code with example usage: obj.test_upload_download() without return types