def METHOD_NAME(cachedir_tree, pillar_cache_dir, pillar_cache_files):
    """
    test pillar.clear_pillar_cache
    """
    MINION_IDS = [
        ["test-host", "another-host"],
        ["test-host"],
        ["test-host", "another-host"],
        ["test-host", "another-host"],
    ]
    _CHECK_MINIONS_RETURN = []
    for entry in MINION_IDS:
        _CHECK_MINIONS_RETURN.append({"minions": entry, "missing": []})
    with patch.dict(pillar_runner.__opts__, {"cachedir": str(cachedir_tree)}):
        with patch(
            "salt.utils.minions.CkMinions.check_minions",
            MagicMock(side_effect=_CHECK_MINIONS_RETURN),
        ):
            expected = {
                "test-host": {
                    "those": ["three", "four", "five"],
                    "that": "two",
                    "this": "one",
                },
                "another-host": {
                    "those": ["eight", "nine", "ten"],
                    "that": "seven",
                    "this": "six",
                },
            }
            ret = pillar_runner.show_pillar_cache()
            assert ret == expected
            ret = pillar_runner.clear_pillar_cache("test-host")
            assert ret == {}
            expected = {
                "another-host": {
                    "those": ["eight", "nine", "ten"],
                    "that": "seven",
                    "this": "six",
                }
            }
            ret = pillar_runner.show_pillar_cache()
            assert ret == expected
            ret = pillar_runner.clear_pillar_cache()
            assert ret == {}