[docs]@declarative_mixinclassAuditColumns:"""Created/Updated At Fields Mixin."""created_at:Mapped[datetime.datetime]=mapped_column(DateTimeUTC(timezone=True),default=lambda:datetime.datetime.now(datetime.timezone.utc),)"""Date/time of instance creation."""updated_at:Mapped[datetime.datetime]=mapped_column(DateTimeUTC(timezone=True),default=lambda:datetime.datetime.now(datetime.timezone.utc),onupdate=lambda:datetime.datetime.now(datetime.timezone.utc),)"""Date/time of instance last update."""@validates("created_at","updated_at")defvalidate_tz_info(self,_:str,value:datetime.datetime)->datetime.datetime:ifvalue.tzinfoisNone:value=value.replace(tzinfo=datetime.timezone.utc)returnvalue