U ey@s&dZdZerddlmZnddZdS)aBFor neatly implementing static typing in pip. `mypy` - the static type analysis tool we use - uses the `typing` module, which provides core functionality fundamental to mypy's functioning. Generally, `typing` would be imported at runtime and used in that fashion - it acts as a no-op at runtime and does not have any run-time overhead by design. As it turns out, `typing` is not vendorable - it uses separate sources for Python 2/Python 3. Thus, this codebase can not expect it to be present. To work around this, mypy allows the typing import to be behind a False-y optional to prevent it from running at runtime and type-comments can be used to remove the need for the types to be accessible directly during runtime. This module provides the False-y guard in a nicely named fashion so that a curious maintainer can reach here to read this. In pip, all static-typing related imports should be guarded as follows: from pip._internal.utils.typing import MYPY_CHECK_RUNNING if MYPY_CHECK_RUNNING: from typing import ... Ref: https://github.com/python/mypy/issues/3216 F)castcCs|S)N)type_valuerr>/tmp/pip-unpacked-wheel-indi3crb/pip/_internal/utils/typing.pyr%srN)__doc__MYPY_CHECK_RUNNINGtypingrrrrrs