then:
        library.exists()
        assertNoFilesInTmp()
        long lastModified = library.lastModified()

        when:
        succeeds("help")

        then:
        library.exists()
        assertNoFilesInTmp()
        lastModified == library.lastModified()
    }

    private void assertNoFilesInTmp() {
        assert tmpDir.testDirectory.listFiles().length == 0
    }