code: def _fit_regularized(self, params):
      # TODO: code will not necessarily be general here. 3 options.
      # 1) setup for scipy.optimize.fmin_sqlsqp
      # 2) setup for cvxopt
      # 3) setup for openopt
      raise NotImplementedError
  
imports: from __future__ import annotations
  from statsmodels.compat.scipy import SP_LT_15, SP_LT_17
  from typing import Any
  from collections.abc import Sequence
  import numpy
  from scipy import optimize
label_desc: Use image node_id 3 for calling the Optimizer obj's underlying member method code with example usage: obj._fit_regularized(params) without return types