code: def update_variances(self, obs_cov, state_cov_diag):
      self["obs_cov"] = obs_cov
      self["state_cov"] = np.diag(state_cov_diag)
  
file_path: statsmodels/examples/python/statespace_tvpvar_mcmc_cfa.py
imports: from importlib import reload
  import numpy
  import pandas
  import statsmodels.api
  import matplotlib.pyplot
  from scipy.stats import invwishart, invgamma
  import arviz
  from statsmodels.tsa.statespace.simulation_smoother import SIMULATION_STATE
label_desc: Use image node_id 2 for calling the TVPVAR obj's underlying member method code with example usage: obj.update_variances(obs_cov, state_cov_diag) without return types