code: def _cumulative_hazard(self, params, T, Xs):
      sigma_2 = np.exp(np.dot(Xs["sigma_"], params["sigma_"]))
      sigma_ = np.sqrt(sigma_2)
      mu_ = np.dot(Xs["mu_"], params["mu_"])
  
      Z = (np.log(T) - mu_) / sigma_
      return -norm.logsf(Z)
  
file_path: lifelines/examples/haft_model.py
imports: import pandas
  import autograd.numpy
  from autograd.scipy.stats import norm
  from lifelines.fitters import ParametricRegressionFitter
  from lifelines import CoxPHFitter, LogNormalAFTFitter
label_desc: Use image node_id 1 for calling the HAFT obj's underlying member method code with example usage: obj._cumulative_hazard(params, T, Xs) and returns: unknown