sqlalchemy (python) 中布尔类型的参数 create_constraint 和名称是什么？

from sqlalchemy import UniqueConstraint
from sqlalchemy.orm import declarative_base

Base = declarative_base()

class User(Base):
    __tablename__ = 'users'
    id = Column(Integer, primary_key=True)
    name = Column(String)
    email = Column(String)

    __table_args__ = (UniqueConstraint('name', 'email', create_constraint=True),)

from sqlalchemy import UniqueConstraint
from sqlalchemy.orm import declarative_base

Base = declarative_base()

class User(Base):
    __tablename__ = 'users'
    id = Column(Integer, primary_key=True)
    name = Column(String)
    email = Column(String)

    __table_args__ = (UniqueConstraint('name', 'email', name='unique_name_email'),)