class_docstr: Nested Conditional Logit (RUNMNL), data handling test
  
  unfinished, does not do anything yet
docstr: these are the V_i
          
docstr_tok: ["these","are","the","V_i"]
code: def xbetas(self, params):
      """these are the V_i"""
  
      res = np.empty((self.nobs, self.nchoices))
      for choiceind in range(self.nchoices):
          res[:, choiceind] = np.dot(
              self.exog_bychoices[choiceind],
              params[self.beta_indices[choiceind]],
          )
      return res
  
file_path: statsmodels/statsmodels/sandbox/regression/runmnl.py
imports: import numpy
  import numpy.lib.recfunctions
  from scipy import optimize
label_desc: Use image node_id 2 for calling the TryNCLogit obj's underlying member method code with example usage: obj.xbetas(params) and returns: res