如何在SQLAlchemy中创建以Interval为主键的表？

from sqlalchemy import create_engine, Column, Interval
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker

engine = create_engine('数据库连接字符串')
Session = sessionmaker(bind=engine)
session = Session()

Base = declarative_base()

class MyTable(Base):
    __tablename__ = 'my_table'
    interval = Column(Interval, primary_key=True)

Base.metadata.create_all(engine)