code: def SetAttributes(self,
                      urn,
                      attributes,
                      to_delete,
                      add_child_index=True,
                      mutation_pool=None):
      
  
      attributes[AFF4Object.SchemaCls.LAST] = [
          rdfvalue.RDFDatetime.Now().SerializeToDataStore()
      ]
      to_delete.add(AFF4Object.SchemaCls.LAST)
      if mutation_pool:
        pool = mutation_pool
      else:
        pool = data_store.DB.GetMutationPool()
  
      pool.MultiSet(urn, attributes, replace=False, to_delete=to_delete)
  
      if add_child_index:
        self._UpdateChildIndex(urn, pool)
      if mutation_pool is None:
        pool.Flush()
docs: Sets the attributes in the data store.