code: def cov_crosssection_0(results, group):
      """this one is still wrong, use cov_cluster instead"""
  
      # TODO: currently used version of groupsums requires 2d resid
      scale = S_crosssection(results.resid[:, None], group)
      scale = np.squeeze(scale)
      cov = _HCCM1(results, scale)
      return cov
  
imports: import numpy
  from statsmodels.tools.grouputils import combine_indices, group_sums
  from statsmodels.stats.moment_helpers import se_cov
label_desc: Use image node_id 15 for calling a global function with example usage: cov_crosssection_0(results, group) and returns: cov