Fixed security analysis warnings

packages/security/lib/src/cookie_signer.dart

@@ -92,7 +92,9 @@ class CookieSigner {
   ///
   /// See [createSignedCookie].
   void writeCookies(ResponseContext res, Iterable<Cookie> cookies) {
-    cookies.forEach((c) => writeCookie(res, c));
+    for (var c in cookies) {
+      writeCookie(res, c);
+    }
   }
 
   /// Returns a new cookie, replacing the value of an input
@@ -104,7 +106,7 @@ class CookieSigner {
   /// Where `sig` is the cookie's value, signed with the [hmac].
   Cookie createSignedCookie(Cookie cookie) {
     return cookieWithNewValue(
-        cookie, cookie.value + '.' + computeCookieSignature(cookie.value));
+        cookie, '${cookie.value}.${computeCookieSignature(cookie.value)}');
   }
 
   /// Returns a new [Cookie] that is the same as the input

packages/security/lib/src/rate_limiting_window.dart

@@ -35,7 +35,7 @@ class RateLimitingWindow<User> {
 
   factory RateLimitingWindow.fromJson(Map<String, dynamic> map) {
     return RateLimitingWindow(
-        (map['user'] as User?)!,
+        (map['user'] as User),
         DateTime.parse(map['start_time'] as String),
         int.parse(map['points_consumed'] as String));
   }

packages/security/pubspec.yaml

@@ -16,6 +16,8 @@ dev_dependencies:
   angel3_validate: ^7.0.0
   belatuk_pretty_logging: ^5.0.0
   test: ^1.21.0
+  logging: ^1.0.0
+  resp_client: ^1.2.0
   lints: ^2.0.0
 dependency_overrides:
   angel3_production: