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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def clean_pip_env() -> Generator[None, None, None]: """A context manager for temporarily removing 'PIP_REQUIRE_VIRTUALENV' from the environment. Since shiv installs via `--target`, we need to ignore venv requirements if they exist. """

    require_venv = os.environ.pop(PIP_REQUIRE_VIRTUALENV, None)

    try:
        yield

    finally:
        if require_venv is not None:
            os.environ[PIP_REQUIRE_VIRTUALENV] = require_venv