code: def to_formula(self, **kwargs) -> str:
      if self.op.name in ["+", "-", "*", "/"]:
          left = self.children[0].to_formula(**kwargs)
          right = self.children[1].to_formula(**kwargs)
          return f"({left}{self.op.name}{right})"
      else:
          result = [self.op.name, "("]
          for i in range(len(self.children)):
              string_i = self.children[i].to_formula(**kwargs)
              result.append(string_i)
              result.append(",")
          result.pop()
          result.append(")")
          return "".join(result)
  
imports: import hashlib
  import itertools
  from typing import Dict, List, Optional, Tuple, Union
  import numpy
  import pandas
  from pandas._typing import DtypeObj
  from upgini.autofe.all_operands import find_op
  from upgini.autofe.operand import Operand, PandasOperand
label_desc: Use image node_id 14 for calling the Feature obj's underlying member method code with example usage: obj.to_formula() and returns: str, left, self, right, str, str