code: def generic_constraint(
      self,
      name: Optional[sqla_compat._ConstraintNameDefined],
      table_name: str,
      type_: Optional[str],
      schema: Optional[str] = None,
      **kw,
  ) -> Any:
      t = self.table(table_name, schema=schema)
      types: Dict[Optional[str], Any] = {
          "foreignkey": lambda name: sa_schema.ForeignKeyConstraint(
              [], [], name=name
          ),
          "primary": sa_schema.PrimaryKeyConstraint,
          "unique": sa_schema.UniqueConstraint,
          "check": lambda name: sa_schema.CheckConstraint(
              "", name=name
          ),
          None: sa_schema.Constraint,
      }
      try:
          const = types[type_]
      except KeyError as ke:
          raise TypeError(
              "'type' can be one of %s"
              % ", ".join(sorted(repr(x) for x in types))
          ) from ke
      else:
          const = const(name=name)
          t.append_constraint(const)
          return const
  
imports: from __future__ import annotations
  from typing import Any
  from typing import Dict
  from typing import List
  from typing import Optional
  from typing import Sequence
  from typing import Tuple
  from typing import TYPE_CHECKING
  from typing import Union
  from sqlalchemy import schema
  from sqlalchemy.sql.schema import Column
  from sqlalchemy.sql.schema import Constraint
  from sqlalchemy.sql.schema import Index
  from sqlalchemy.types import Integer
  from sqlalchemy.types import NULLTYPE
  from ..None import util
  from ..util import sqla_compat
label_desc: Use image node_id 6 for calling the SchemaObjects obj's underlying member method code with example usage: obj.generic_constraint(name, table_name, type_, schema) and returns: const