docstr: A list of variable names in the feature representation
docstr_tok: ["A","list","of","variable","names","in","the","feature","representation"]
code: def variable_names(self):
      """
      A list of variable names in the feature representation
      """
      tokens = _get_tokens(self._expression)
      return [
          x
          for x in tokens
          if x not in OPERATORS + ["(", ")"] and not is_number(x)
      ]
  
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 2 for calling the Feature obj's underlying member method code with example usage: obj.variable_names() and returns: unknown