code: def active_run(self):
      if not self.runs:
          return None
      return self.runs[-1]
  
imports: import secrets
  from contextlib import contextmanager
  from pycaret.loggers.base_logger import BaseLogger
  from pycaret.utils.generic import mlflow_remove_bad_chars
label_desc: Use image node_id 3 for calling the MlflowLogger obj's underlying member method code with example usage: obj.active_run() and returns: self, None