code: def _log_multivariate_normal_density_spherical(X, means, covars):
      
      cv = covars.copy()
      if covars.ndim == 1:
          cv = cv[:, np.newaxis]
      if cv.shape[1] == 1:
          cv = np.tile(cv, (1, X.shape[-1]))
      return _log_multivariate_normal_density_diag(X, means, cv)
docs: Compute Gaussian log-density at X for a spherical model.