diff --git a/Sources/Tetra/Concurrency/CoreDataStack+Concurrency.swift b/Sources/Tetra/Concurrency/CoreDataStack+Concurrency.swift
index c4bf961..e552a0b 100644
--- a/Sources/Tetra/Concurrency/CoreDataStack+Concurrency.swift
+++ b/Sources/Tetra/Concurrency/CoreDataStack+Concurrency.swift
@@ -14,19 +14,6 @@ import CoreData
 @available(iOS 13.0, tvOS 13.0, macCatalyst 13.0, watchOS 6.0, macOS 10.15, *)
 public extension NSPersistentContainer {
     
-    @inlinable
-    func loadPersistent() async throws -> NSPersistentStoreDescription {
-        try await withUnsafeThrowingContinuation { continuation in
-            loadPersistentStores {
-                if let error = $1 {
-                    continuation.resume(throwing: error)
-                } else {
-                    continuation.resume(returning: $0)
-                }
-            }
-        }
-    }
-    
     @available(iOS, introduced: 13.0, deprecated: 15.0, renamed: "performBackgroundTask(_:)")
     @available(tvOS, introduced: 13.0, deprecated: 15.0, renamed: "performBackgroundTask(_:)")
     @available(macCatalyst, introduced: 13.0, deprecated: 15.0, renamed: "performBackgroundTask(_:)")
diff --git a/Sources/Tetra/Concurrency/Dispatch+Extension.swift b/Sources/Tetra/Concurrency/Dispatch+Extension.swift
index 52c701d..5f732fb 100644
--- a/Sources/Tetra/Concurrency/Dispatch+Extension.swift
+++ b/Sources/Tetra/Concurrency/Dispatch+Extension.swift
@@ -27,7 +27,6 @@ public extension Task where Success == Never, Failure == Never {
      */
     @inlinable
     static func sleep(until wallDeadline:DispatchWallTime, tolerance:DispatchTimeInterval? = nil) async throws {
-        try await Task.sleep(nanoseconds: 1000)
         try await dispatchTimerSleep(wait: wallDeadline, leeway: tolerance)
     }
     
diff --git a/Sources/Tetra/Foundation/Codable/DecodingTypeError.swift b/Sources/Tetra/Foundation/Codable/DecodingTypeError.swift
deleted file mode 100644
index 0de0ec0..0000000
--- a/Sources/Tetra/Foundation/Codable/DecodingTypeError.swift
+++ /dev/null
@@ -1,59 +0,0 @@
-//
-//  DecodingTypeError.swift
-//  
-//
-//  Created by pbk on 2023/01/30.
-//
-
-import Foundation
-
-/// `DecodingError.typeMismatch` wrapper type to unwind stack of decoding
-@usableFromInline
-struct DecodingTypeError {
- 
-    @usableFromInline
-    let expectedType:Any.Type
-    @usableFromInline
-    let context:DecodingError.Context
-    
-    @usableFromInline
-    internal init(expectedType: Any.Type, context: DecodingError.Context) {
-        self.expectedType = expectedType
-        self.context = context
-    }
-    
-}
-
-extension DecodingTypeError: LocalizedError {
-    
-    @usableFromInline
-    var decodingError:DecodingError {
-        .typeMismatch(expectedType, context)
-    }
-    
-    @usableFromInline
-    var localizedDescription:String {
-        decodingError.localizedDescription
-    }
-    
-    @usableFromInline
-    var errorDescription: String? {
-        decodingError.errorDescription
-    }
-    
-    @usableFromInline
-    var failureReason: String? {
-        decodingError.failureReason
-    }
-    
-    @usableFromInline
-    var helpAnchor: String? {
-        decodingError.helpAnchor
-    }
-    
-    @usableFromInline
-    var recoverySuggestion: String? {
-        decodingError.recoverySuggestion
-    }
-    
-}
diff --git a/Tests/TetraTests/RunLoopSchedulerTests.swift b/Tests/TetraTests/RunLoopSchedulerTests.swift
index 783c7a6..24d8321 100644
--- a/Tests/TetraTests/RunLoopSchedulerTests.swift
+++ b/Tests/TetraTests/RunLoopSchedulerTests.swift
@@ -43,7 +43,7 @@ final class RunLoopSchedulerTests: XCTestCase {
         let scheduler = await RunLoopScheduler(async: (), config: .init(qos: .background))
         let name = Notification.Name(UUID().uuidString)
         let object = NSObject()
-        expectation(forNotification: name, object: object, notificationCenter: .default) { notification in
+        let expect1 = expectation(forNotification: name, object: object, notificationCenter: .default) { notification in
             XCTAssertTrue(notification.userInfo?["A"] as? String == "B")
             return true
         }
@@ -63,8 +63,11 @@ final class RunLoopSchedulerTests: XCTestCase {
 
             }
         }
-        await waitForExpectations(timeout: 1)
-        expectation(forNotification: name, object: object, notificationCenter: .default) {
+        await withUnsafeContinuation{
+            wait(for: [expect1], timeout: 1)
+            $0.resume()
+        }
+        let expect2 = expectation(forNotification: name, object: object, notificationCenter: .default) {
             XCTAssertTrue($0.userInfo?["A"] as? String == "C")
             return true
         }
@@ -75,7 +78,10 @@ final class RunLoopSchedulerTests: XCTestCase {
                 continuation.resume()
             }
         }
-        await waitForExpectations(timeout: 1)
+        await withUnsafeContinuation{
+            wait(for: [expect2], timeout: 1)
+            $0.resume()
+        }
     }
 
 }