code: def __str__(self):
      return " ".join(self._expression.split())
  
file_path: AIX360/aix360/algorithms/rule_induction/trxf/core/feature.py
imports: import numbers
  import tokenize
  from io import BytesIO
  from typing import Dict, Any
label_desc: Use image node_id 6 for calling the Feature obj's underlying member method code with example usage: obj.__str__() and returns: str