code: private List<String> getIdList(final List<? extends AuditModel> toDelete) {
          List<String> ids = new ArrayList<>(toDelete.size());
          for (AuditModel auditModel : toDelete) {
              ids.add(auditModel.getId());
          }
          return ids;
      }
docs: Gets the list of Id's of the given List of Models.
  
  @param toDelete List of AuditModels to get there Ids.
  @return A List of Ids.