class_docstr: A wrapper class that uses IV2SLS from statsmodel
  
  A linear 2SLS model that estimates the average treatment effect with endogenous treatment variable.
docstr: Returns the average treatment effect and its estimated standard error
  
  Returns:
      (float): average treatment effect
      (float): standard error of the estimation
docstr_tok: ["Returns","the","average","treatment","effect","and","its","estimated","standard","error","Returns",":","(","float",")",":","average","treatment","effect","(","float",")",":","standard","error","of","the","estimation"]
code: def predict(self):
      """Returns the average treatment effect and its estimated standard error
  
      Returns:
          (float): average treatment effect
          (float): standard error of the estimation
      """
  
      return self.iv_fit.params[-1], self.iv_fit.bse[-1]
  
file_path: causalml/causalml/inference/iv/iv_regression.py
imports: import numpy
  from causalml.inference.meta.utils import convert_pd_to_np
  import statsmodels.api
  from statsmodels.sandbox.regression.gmm import IV2SLS
label_desc: Use image node_id 3 for calling the IVRegressor obj's underlying member method code with example usage: obj.predict() and returns: self,  self