return err
		}
	}
	return nil
}

// DropTable drop table for values
func (m Migrator) DropTable(values ...interface{}) error {
	values = m.ReorderModels(values, false)
	for i := len(values) - 1; i >= 0; i-- {
		tx := m.DB.Session(&gorm.Session{})
		if err := m.RunWithValue(values[i], func(stmt *gorm.Statement) error {
			return tx.Exec("DROP TABLE IF EXISTS ?", m.CurrentTable(stmt)).Error
		}); err != nil {

In that case, you can simply swap the standard `dataclasses` with `pydantic.dataclasses`, which is a drop-in replacement:

{* ../../docs_src/dataclasses/tutorial003.py hl[1,5,8:11,14:17,23:25,28] *}

1. We still import `field` from standard `dataclasses`.

2. `pydantic.dataclasses` is a drop-in replacement for `dataclasses`.

3. The `Author` dataclass includes a list of `Item` dataclasses.

        // collect drop list
        for (MetadataGraphVertex v : g.getVertices()) {
            if (!visited.contains(v)) {
                dropList.add(v);
            }
        }

        if (dropList.isEmpty()) {
            return g;
        }

        // now - drop vertices
        TreeSet<MetadataGraphVertex> vertices = g.getVertices();

		t.Fatalf("Failed to drop view, got %v", err)
	}

	query = DB.Model(&User{}).Where("age > ?", 20)
	if err := DB.Migrator().CreateView("users_view", gorm.ViewOption{Query: query}); err != nil {
		t.Fatalf("Failed to crate view, got %v", err)
	}
	if err := DB.Migrator().DropView("users_view"); err != nil {
		t.Fatalf("Failed to drop view, got %v", err)
	}
}

      var value =
        if (equalsSign < pairEnd) {
          header.trimSubstring(equalsSign + 1, pairEnd)
        } else {
          ""
        }

      // If the value is "quoted", drop the quotes.
      if (value.startsWith("\"") && value.endsWith("\"") && value.length >= 2) {
        value = value.substring(1, value.length - 1)
      }

      result.add(
        Cookie
          .Builder()

	DB.Migrator().DropTable("user_friends", "user_speaks")

	if err = DB.Migrator().DropTable(allModels...); err != nil {
		log.Printf("Failed to drop table, got error %v\n", err)
		os.Exit(1)
	}

	if err = DB.AutoMigrate(allModels...); err != nil {
		log.Printf("Failed to auto migrate, but got error %v\n", err)
		os.Exit(1)
	}

        if (index != -1) { // Index -1 == new header.
          delta -= dynamicTable[dynamicTableIndex(index)]!!.hpackSize
        }

        // if the new or replacement header is too big, drop all entries.
        if (delta > maxDynamicTableByteCount) {
          clearDynamicTable()
          return
        }

        // Evict headers to the required length.

	}

	if len(line) == 0 {
		if err != nil {
			line = nil
		}
		return
	}
	err = nil

	if line[len(line)-1] == '\n' {
		drop := 1
		if len(line) > 1 && line[len(line)-2] == '\r' {
			drop = 2
		}
		line = line[:len(line)-drop]
	}
	return
}

// collectFragments reads until the first occurrence of delim in the input. It

      } else {
        // Otherwise the rule is for a public suffix, so we must take one more label.
        domainLabels.size - (rule.size + 1)
      }

    return splitDomain(domain).asSequence().drop(firstLabelOffset).joinToString(".")
  }

  private fun splitDomain(domain: String): List<String> {
    val domainLabels = domain.split('.')

    if (domainLabels.last() == "") {

        @Override
        public boolean reportProblem(P problem) {
            requireNonNull(problem, "problem");
            // first apply filter
            if (!filter.test(problem)) {
                // drop without counting towards preserved problems
                return false;
            }
            int currentCount = totalCount.incrementAndGet();
            getCounter(problem.getSeverity()).increment();