_OBJC_CLASS_$_RCTReconnectingWebSocket

```
Undefined symbols for architecture x86_64:
  "_OBJC_CLASS_$_RCTReconnectingWebSocket", referenced from:
      objc-class-ref in libReact.a(RCTPackagerConnection.o)
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
```
Please help me. Thx