code: def loglikeobs(self, params):
      beta = params[:-1]
      sigma = params[-1]
      xb = np.dot(self.exog, beta)
      return stats.norm.logpdf(self.endog, loc=xb, scale=sigma)
  
file_path: statsmodels/statsmodels/examples/ex_generic_mle.py
imports: from functools import partial
  import numpy
  from scipy import stats
  import statsmodels.api
  from statsmodels.base.model import GenericLikelihoodModel
  from statsmodels.tools.numdiff import approx_fprime, approx_hess
label_desc: Use image node_id 2 for calling the MygMLE obj's underlying member method code with example usage: obj.loglikeobs(params) and returns: stats