class_docstr: experimental class for Covariance of AR process
  classmethod? staticmethods?
class_docstr_tok: ["experimental","class","for","Covariance","of","AR","process","classmethod","?","staticmethods","?"]
code: def corr(self, k_vars=None):
      if k_vars is None:
          k_vars = len(self.ar)  # TODO: this could move into corr_arr
      return corr_ar(k_vars, self.ar)
  
file_path: statsmodels/statsmodels/sandbox/panel/correlation_structures.py
imports: import numpy
  from statsmodels.regression.linear_model import yule_walker
  from statsmodels.stats.moment_helpers import cov2corr
label_desc: Use image node_id 4 for calling the ARCovariance obj's underlying member method code with example usage: obj.corr(k_vars) and returns: corr_ar