diff --git a/Example/Pigeon/AppDelegate.swift b/Example/Pigeon/AppDelegate.swift
index 03a40b1..4f4d1b4 100644
--- a/Example/Pigeon/AppDelegate.swift
+++ b/Example/Pigeon/AppDelegate.swift
@@ -14,14 +14,15 @@ import Pigeon
 class AppDelegate: UIResponder, UIApplicationDelegate {
 
     var window: UIWindow?
-
-    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
+    
+    func application(_ application: UIApplication,
+                     didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
         let controller = ViewController()
         window = UIWindow(frame: UIScreen.main.bounds)
-        window!.rootViewController = controller
-        window!.makeKeyAndVisible()
-        
+        if let window = window {
+            window.rootViewController = controller
+            window.makeKeyAndVisible()
+        }
         return true
     }
 }
-
diff --git a/Example/Pigeon/ContentView.swift b/Example/Pigeon/ContentView.swift
index 38e2823..8ee5b1f 100644
--- a/Example/Pigeon/ContentView.swift
+++ b/Example/Pigeon/ContentView.swift
@@ -19,7 +19,7 @@ struct ContentView: View {
             invalidationPolicy: .expiresAfter(1000),
             usagePolicy: .useInsteadOfFetching
         ),
-        fetcher: { request, page in
+        fetcher: { _, page in
             print("Fetching page no. \(page)")
             return GetCardsRequest()
                 .execute()
@@ -43,13 +43,18 @@ struct UsersList: View {
         },
         behavior: .startImmediately(1),
         cache: UserDefaultsQueryCache.shared,
-        fetcher: { id in
-            URLSession.shared
-                .dataTaskPublisher(for: URL(string: "https://jsonplaceholder.typicode.com/users/")!)
-                .map(\.data)
-                .decode(type: [User].self, decoder: JSONDecoder())
-                .receive(on: DispatchQueue.main)
-                .eraseToAnyPublisher()
+        fetcher: { _ in
+            let url = URL(string: "https://jsonplaceholder.typicode.com/users/")
+            if let url = url {
+                return URLSession.shared
+                    .dataTaskPublisher(for: url)
+                    .map(\.data)
+                    .decode(type: [User].self, decoder: JSONDecoder())
+                    .receive(on: DispatchQueue.main)
+                    .eraseToAnyPublisher()
+            } else {
+                return AnyPublisher<[User], Error>(Empty<[User], Error>())
+            }
         }
     )
     
diff --git a/Example/Pigeon/ViewController.swift b/Example/Pigeon/ViewController.swift
index 316260e..283ceb2 100644
--- a/Example/Pigeon/ViewController.swift
+++ b/Example/Pigeon/ViewController.swift
@@ -18,8 +18,8 @@ class ViewController: UIHostingController<ContentView> {
         super.init(rootView: ContentView())
     }
     
-    @objc required dynamic init?(coder aDecoder: NSCoder) {
+    @objc
+    dynamic required init?(coder aDecoder: NSCoder) {
         fatalError("init(coder:) has not been implemented")
     }
-    
 }
diff --git a/Example/Tests/Tests.swift b/Example/Tests/Tests.swift
index 6e740e4..840e3c1 100644
--- a/Example/Tests/Tests.swift
+++ b/Example/Tests/Tests.swift
@@ -20,9 +20,8 @@ class Tests: XCTestCase {
     
     func testPerformanceExample() {
         // This is an example of a performance test case.
-        self.measure() {
+        self.measure {
             // Put the code you want to measure the time of here.
         }
     }
-    
 }
diff --git a/Pigeon/Classes/Cache/QueryCacheType.swift b/Pigeon/Classes/Cache/QueryCacheType.swift
index fa517fc..6241f9f 100644
--- a/Pigeon/Classes/Cache/QueryCacheType.swift
+++ b/Pigeon/Classes/Cache/QueryCacheType.swift
@@ -26,7 +26,7 @@ public struct QueryCache {
         self.wrappedCache = wrappedCache
     }
     
-    private(set) public static var global: QueryCacheType = inMemory.wrappedCache
+    public private(set) static var global: QueryCacheType = inMemory.wrappedCache
     public static func setGlobal(_ wrapper: QueryCache) {
         QueryCache.global = wrapper.wrappedCache
     }
diff --git a/Pigeon/Classes/PaginatedQuery.swift b/Pigeon/Classes/PaginatedQuery.swift
index ed4f04c..30c6228 100644
--- a/Pigeon/Classes/PaginatedQuery.swift
+++ b/Pigeon/Classes/PaginatedQuery.swift
@@ -9,7 +9,9 @@
 import Foundation
 import Combine
 
-public final class PaginatedQuery<Request, PageIdentifier: PaginatedQueryKey, Response: Codable & Sequence>: ObservableObject, QueryType, QueryInvalidationListener {
+public final class PaginatedQuery< Request,
+                                 PageIdentifier: PaginatedQueryKey,
+                                 Response: Codable & Sequence>: ObservableObject, QueryType, QueryInvalidationListener {
     
     public enum FetchingBehavior {
         case startWhenRequested
@@ -18,21 +20,17 @@ public final class PaginatedQuery<Request, PageIdentifier: PaginatedQueryKey, Re
     public typealias State = QueryState<Response>
     public typealias QueryFetcher = (Request, PageIdentifier) -> AnyPublisher<Response, Error>
     
-    @Published private(set) public var items: [Response.Element] = []
+    @Published public private(set) var items: [Response.Element] = []
     @Published private var internalState = State.idle
-    @Published private(set) public var currentPage: PageIdentifier
+    @Published public private(set) var currentPage: PageIdentifier
     private var internalValuePublisher: AnyPublisher<Response, Never> {
         $internalState
-            .map { $0.value }
-            .filter({ $0 != nil })
-            .map { $0! }
+            .compactMap { $0.value }
             .eraseToAnyPublisher()
     }
     public var valuePublisher: AnyPublisher<Response, Never> {
         statePublisher
-            .map { $0.value }
-            .filter({ $0 != nil })
-            .map { $0! }
+            .compactMap { $0.value }
             .eraseToAnyPublisher()
     }
     public var state: QueryState<Response> {
@@ -44,7 +42,11 @@ public final class PaginatedQuery<Request, PageIdentifier: PaginatedQueryKey, Re
         case let .failed(error):
             return .failed(error)
         case .succeed:
-            return .succeed(items as! Response)
+            if let items = items as? Response {
+                return .succeed(items)
+            } else {
+                return .failed(ItemError.castFail)
+            }
         }
     }
     public var statePublisher: AnyPublisher<QueryState<Response>, Never> {
@@ -112,7 +114,6 @@ public final class PaginatedQuery<Request, PageIdentifier: PaginatedQueryKey, Re
                     internalState = .succeed(cachedResponse)
                 }
             }
-            break
         case let .startImmediately(request):
             refetchPage(request: request, page: currentPage)
         }
@@ -203,3 +204,7 @@ public final class PaginatedQuery<Request, PageIdentifier: PaginatedQueryKey, Re
             .store(in: &cancellables)
     }
 }
+
+enum ItemError: Error {
+    case castFail
+}
diff --git a/Pigeon/Classes/Query.swift b/Pigeon/Classes/Query.swift
index 1019c8a..45f00d2 100644
--- a/Pigeon/Classes/Query.swift
+++ b/Pigeon/Classes/Query.swift
@@ -22,15 +22,13 @@ public final class Query<Request, Response: Codable>: ObservableObject, QueryTyp
     public typealias State = QueryState<Response>
     public typealias QueryFetcher = (Request) -> AnyPublisher<Response, Error>
     
-    @Published private(set) public var state = State.idle
+    @Published public private(set) var state = State.idle
     public var statePublisher: AnyPublisher<QueryState<Response>, Never> {
         return $state.eraseToAnyPublisher()
     }
     public var valuePublisher: AnyPublisher<Response, Never> {
         $state
-            .map { $0.value }
-            .filter({ $0 != nil })
-            .map { $0! }
+            .compactMap { $0.value }
             .eraseToAnyPublisher()
     }
     private let key: QueryKey
@@ -102,7 +100,6 @@ public final class Query<Request, Response: Codable>: ObservableObject, QueryTyp
                     state = .succeed(cachedResponse)
                 }
             }
-            break
         case let .startImmediately(request):
             refetch(request: request)
         }
diff --git a/Pigeon/Classes/QueryConsumer.swift b/Pigeon/Classes/QueryConsumer.swift
index 4130b4c..0339731 100644
--- a/Pigeon/Classes/QueryConsumer.swift
+++ b/Pigeon/Classes/QueryConsumer.swift
@@ -11,7 +11,6 @@ import Combine
 
 extension Query {
     public final class Consumer: ObservableObject, QueryType {
-        public typealias State = QueryState<Response>
         private let key: QueryKey
         private let query: AnyQuery<Request, Response>
         public var state: State { query.state }
@@ -20,9 +19,7 @@ extension Query {
         }
         public var valuePublisher: AnyPublisher<Response, Never> {
             query.statePublisher
-                .map { $0.value }
-                .filter({ $0 != nil })
-                .map { $0! }
+                .compactMap { $0.value }
                 .eraseToAnyPublisher()
         }
         private var cancellables = Set<AnyCancellable>()
diff --git a/Pigeon/Classes/Utils/QueryCacheConfig.swift b/Pigeon/Classes/Utils/QueryCacheConfig.swift
index ecccd08..4d28d2f 100644
--- a/Pigeon/Classes/Utils/QueryCacheConfig.swift
+++ b/Pigeon/Classes/Utils/QueryCacheConfig.swift
@@ -29,7 +29,7 @@ public struct QueryCacheConfig {
         self.usagePolicy = usagePolicy
     }
     
-    private(set) public static var global: QueryCacheConfig = .init()
+    public private(set) static var global: QueryCacheConfig = .init()
     public static func setGlobal(_ config: QueryCacheConfig) {
         QueryCacheConfig.global = config
     }
diff --git a/Pigeon/Classes/Utils/QueryInvalidationListener.swift b/Pigeon/Classes/Utils/QueryInvalidationListener.swift
index 1c6cba9..cda367c 100644
--- a/Pigeon/Classes/Utils/QueryInvalidationListener.swift
+++ b/Pigeon/Classes/Utils/QueryInvalidationListener.swift
@@ -17,10 +17,9 @@ public extension QueryInvalidationListener {
     func listenQueryInvalidation(for key: QueryKey) -> AnyPublisher<QueryInvalidator.TypedParameters<Request>, Never> {
         NotificationCenter.default.publisher(for: key.invalidationNotificationName)
             .map(\.object)
-            .map { ($0 as? QueryInvalidator.Parameters)?
-                .toTypedParameters(of: Request.self) }
-            .filter({ $0 != nil })
-            .map { $0! }
+            .compactMap { ($0 as? QueryInvalidator.Parameters)?
+                .toTypedParameters(of: Request.self)
+            }
             .eraseToAnyPublisher()
     }
 }
diff --git a/Pigeon/Classes/Utils/QueryRegistry.swift b/Pigeon/Classes/Utils/QueryRegistry.swift
index 9bcabe9..8a9a267 100644
--- a/Pigeon/Classes/Utils/QueryRegistry.swift
+++ b/Pigeon/Classes/Utils/QueryRegistry.swift
@@ -6,6 +6,7 @@
 //
 
 import Foundation
+import Combine
 
 final class QueryRegistry {
     private var queries: [QueryKey: Any] = [:]
@@ -25,6 +26,15 @@ final class QueryRegistry {
     }
     
     func resolve<Request, Response>(for key: QueryKey) -> AnyQuery<Request, Response> {
-        return queries[key] as! AnyQuery<Request, Response>
+        //let queries: AnyQuery<Request, Response>
+        if let queries = queries[key] as? AnyQuery<Request, Response> {
+            return queries
+        }
+        //todo fix stateGetter context
+        return AnyQuery<Request, Response>(stateGetter: { QueryState.loading },
+                                           statePublisherGetter: {
+                                            AnyPublisher<QueryState<Response>, Never>(
+                                                Empty<QueryState<Response>, Never>())
+                                           })
     }
 }