def test_read_file_fails_silently_by_default(self):
        root = self.create_basic_filesystem()

        dir1 = Directory(root)("Dir1")
        self.assertIsNone(dir1.read_file("FileXXXX"))
    def test_read_file_fails_with_right_exception_if_indicated(self):
        root = self.create_basic_filesystem()

        dir1 = Directory(root)("Dir1")
        with self.assertRaises(FileNotFoundError):
            dir1.read_file("FileXXXX", raiseException=True)
    def test_read_file_can_read_a_file(self):
        root = self.create_basic_filesystem()

        dir1 = Directory(root)("Dir1")
        self.assertIsNotNone(dir1.read_file("File1"))