class_docstr: Sends a message to Slack upon completion/failing of an experiment.
code: def get_failed_text(self):
      return self.failed_text.format(**self.run)
  
file_path: sacred/sacred/observers/slack.py
imports: from sacred.observers.base import RunObserver, td_format
  from sacred.config.config_files import load_config_file
  import json
label_desc: Use image node_id 6 for calling the SlackObserver obj's underlying member method code with example usage: obj.get_failed_text() and returns: self