class_docstr: Base class for survival loss functions.
class_docstr_tok: ["Base","class","for","survival","loss","functions","."]
code: def init_estimator(self):
      return DummySurvivalEstimator(strategy="constant", constant=0.0)
  
imports: from abc import ABCMeta
  import numpy
  from sklearn.dummy import DummyRegressor
  from sklearn.ensemble._gb_losses import RegressionLossFunction
  from sklearn.utils.extmath import squared_norm
  from ..nonparametric import ipc_weights
  from ._coxph_loss import coxph_loss, coxph_negative_gradient
label_desc: Use image node_id 1 for calling the SurvivalLossFunction obj's underlying member method code with example usage: obj.init_estimator() and returns: DummySurvivalEstimator