code: def neutralize_variables(self, tax_benefit_system):
          
          for variable_name, variable in tax_benefit_system.variables.items():
              if variable.formulas:
                  continue
              if self.used_as_input_variables and (variable_name in self.used_as_input_variables):
                  continue
              if self.non_neutralizable_variables and (variable_name in self.non_neutralizable_variables):
                  continue
              if self.weight_column_name_by_entity and (variable_name in self.weight_column_name_by_entity.values()):
                  continue
  
              tax_benefit_system.neutralize_variable(variable_name)
docs: Neutralizing input variables not in input dataframe and keep some crucial variables