class_docstr: Test case of valid towhee command
docstr: target: test command 'downloadS3' relative path
  method: use downloadS3 to download files in S3 relative path without bucket_name
  expected: download successfully
code: def test_command_downloadS3_relative_path(self):
      """
      target: test command 'downloadS3' relative path
      method: use downloadS3 to download files in S3 relative path without bucket_name
      expected: download successfully
      """
      if os.path.exists("./test.pt"):
          os.system("rm test.pt")
      res = os.popen("towhee downloadS3 -pl ./ -pb test/test.pt").read()
      assert "success" in res
      if os.path.exists("./test.pt"):
          os.system("rm test.pt")
          return True
      else:
          return False
  
file_path: towhee/tests/testcases/test_command.py
imports: import os
  import sys
  import towhee
label_desc: Use image node_id 2 for calling the TestCommandValid obj's underlying member method code with example usage: obj.test_command_downloadS3_relative_path() and returns: True, False