var _a, _a$b$c, _a$b, _a2;

(_a = a) == null ? void 0 : delete _a.b;

(_a2 = a) == null ? void 0 : (_a$b = _a2.b) == null ? void 0 : (_a$b$c = _a$b.c) == null ? void 0 : delete _a$b$c.d;