class_docstr: Test case of invalid towhee command
docstr: target: test command 'lsS3' absolute path
  method: use lsS3 to list files in S3 absolute path with bucket_name
  expected: get error message
code: def test_command_lsS3_absolute_path(self):
      """
      target: test command 'lsS3' absolute path
      method: use lsS3 to list files in S3 absolute path with bucket_name
      expected: get error message
      """
      res = os.popen(
          "towhee lsS3 -p s3://pretrainedweights.towhee.io/test/test.pt"
      ).read()
      assert "not exist" in res
      return True
  
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 TestCommandInvalid obj's underlying member method code with example usage: obj.test_command_lsS3_absolute_path() and returns: True