code: def setUp(self):
      self.stash_session()
      self.stash_files()
      defaults = dict(
          files.FILE_CONTENT[files.CREDENTIALS_FILE],
          **files.FILE_CONTENT[files.CONFIG_FILE],
      )
      session.sign_in(**defaults)
  
file_path: plotly.py/packages/python/chart-studio/chart_studio/tests/utils.py
imports: import copy
  from unittest import TestCase
  from chart_studio import session, files, utils
  from plotly.files import ensure_writable_plotly_dir
label_desc: Use image node_id 3 for calling the PlotlyTestCase obj's underlying member method code with example usage: obj.setUp() without return types