on error ReferenceError: WebSocket is not defined about apollo-client HOT 5 OPEN

[                                                                                                                       
  {                                                                                                                                      
    message: 'Cannot query field "eid" on type "IFooBar". Did you mean "_eid"?',                                       
    locations: [ [Object] ]                                                                                                              
  }                                                                                                                                      
]

    const wsLink = new GraphQLWsLink(createClient({
     url: 'wss://my-url/graphql',
      webSocketImpl: WebSocket,
      connectionParams: {
           ...
      }
    }));