class_docstr: Class for estimating regularized inverse covariance with
  nodewise regression
  
  Parameters
  ----------
  exog : array_like
      A weighted design matrix for covariance
  
  Attributes
  ----------
  exog : array_like
      A weighted design matrix for covariance
  alpha : scalar
      Regularizing constant
code: def approx_inv_cov(self):
      return self._approx_inv_cov
  
file_path: statsmodels/statsmodels/stats/regularized_covariance.py
imports: from statsmodels.regression.linear_model import OLS
  import numpy
label_desc: Use image node_id 3 for calling the RegularizedInvCovariance obj's underlying member method code with example usage: obj.approx_inv_cov() and returns: self