code: func (cps ComparablePrincipalSets) ExcludeIndices(mapping map[int][]int) ComparablePrincipalSets {
  	var res ComparablePrincipalSets
  	for i, set := range cps {
  		if _, exists := mapping[i]; exists {
  			continue
  		}
  		res = append(res, set)
  	}
  	return res
  }
docs: // ExcludeIndices returns a ComparablePrincipalSets without the given indices found in the keys