# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import typing as ty


# Workaround Python's lack of an undefined sentinel
# https://python-patterns.guide/python/sentinel-object/
class Unset:
    def __bool__(self) -> ty.Literal[False]:
        return False


UNSET: Unset = Unset()