code: def validate_calculation(
      self, input_columns: List[str], **kwargs
  ) -> Tuple[str, List[str]]:
      if not kwargs.get(MAIN_COLUMN):
          raise ValueError(
              f"Expected argument {MAIN_COLUMN} for grouping operator {self.name} not found"
          )
      group_column = kwargs[MAIN_COLUMN]
      value_columns = [
          col for col in input_columns if col != group_column
      ]
  
      return group_column, value_columns
  
imports: from pydantic import BaseModel
  from typing import Dict, List, Optional, Tuple, Union
  import abc
  import pandas
  import numpy
label_desc: Use image node_id 1 for calling the VectorizableMixin obj's underlying member method code with example usage: obj.validate_calculation(input_columns) and returns: group_column,  value_columns