code: func (mc MongoClient) deleteById(col string, id string) error {
  	s := mc.getSessionCopy()
  	defer s.Close()
  
  	query, err := idToBsonM(id)
  	if err != nil {
  		return err
  	}
  	return errorMap(s.DB(mc.database.Name).C(col).Remove(query))
  }
docs: // Delete from the collection based on ID