fix: Fix analysis issues.

Author: kinyoklion

packages/event_source_client/lib/src/events.dart

@@ -89,14 +89,3 @@ final class OpenEvent implements Event {
           headers!.entries.map((item) => Object.hash(item.key, item.value)))
       : null.hashCode;
 }
-
-bool isMessageEvent(Event event) {
-  {
-    switch (event) {
-      case MessageEvent():
-        return true;
-      default:
-        return false;
-    }
-  }
-}

packages/event_source_client/lib/src/sse_client_http.dart

@@ -4,7 +4,6 @@ import 'dart:math' as math;
 import 'package:http/http.dart' as http;
 
 import '../launchdarkly_event_source_client.dart';
-import 'events.dart' show isMessageEvent;
 import 'state_idle.dart';
 import 'state_value_object.dart';
 

packages/event_source_client/test/sse_client_http_test.dart

@@ -7,7 +7,6 @@ import 'dart:math' as math;
 import 'package:http/http.dart';
 import 'package:launchdarkly_event_source_client/launchdarkly_event_source_client.dart';
 import 'package:launchdarkly_event_source_client/src/http_consts.dart';
-import 'package:launchdarkly_event_source_client/src/events.dart';
 import 'package:launchdarkly_event_source_client/src/sse_client_http.dart';
 import 'package:launchdarkly_event_source_client/src/state_connected.dart';
 import 'package:launchdarkly_event_source_client/src/state_connecting.dart';