class_docstr: deals with inheritance and many-to-many relationships
class_docstr_tok: ["deals","with","inheritance","and","many-to-many","relationships"]
code: def define_tables(cls, metadata):
      global foo, bar, blub, bar_foo, blub_bar, blub_foo
  
      # the 'data' columns are to appease SQLite which can't handle a blank
      # INSERT
      foo = Table(
          "foo",
          metadata,
          Column(
              "id",
              Integer,
              normalize_sequence(
                  config, Sequence("foo_seq", optional=True)
              ),
              primary_key=True,
          ),
          Column("data", String(20)),
      )
  
      bar = Table(
          "bar",
          metadata,
          Column("id", Integer, ForeignKey("foo.id"), primary_key=True),
          Column("bar_data", String(20)),
      )
  
      blub = Table(
          "blub",
          metadata,
          Column("id", Integer, ForeignKey("bar.id"), primary_key=True),
          Column("blub_data", String(20)),
      )
  
      bar_foo = Table(
          "bar_foo",
          metadata,
          Column("bar_id", Integer, ForeignKey("bar.id")),
          Column("foo_id", Integer, ForeignKey("foo.id")),
      )
  
      blub_bar = Table(
          "bar_blub",
          metadata,
          Column("blub_id", Integer, ForeignKey("blub.id")),
          Column("bar_id", Integer, ForeignKey("bar.id")),
      )
  
      blub_foo = Table(
          "blub_foo",
          metadata,
          Column("blub_id", Integer, ForeignKey("blub.id")),
          Column("foo_id", Integer, ForeignKey("foo.id")),
      )
  
imports: from sqlalchemy import Column
  from sqlalchemy import ForeignKey
  from sqlalchemy import Integer
  from sqlalchemy import Sequence
  from sqlalchemy import String
  from sqlalchemy import Table
  from sqlalchemy.orm import class_mapper
  from sqlalchemy.orm import relationship
  from sqlalchemy.testing import config
  from sqlalchemy.testing import eq_
  from sqlalchemy.testing import fixtures
  from sqlalchemy.testing.fixtures import fixture_session
  from sqlalchemy.testing.provision import normalize_sequence
label_desc: Use image node_id 1 for calling the InheritTest3 obj's underlying member method code with example usage: obj.define_tables(cls, metadata) without return types