     public func synchronize() -> Resolver {
         return SynchronizedResolver(container: self)
     }
+}
 
 // MARK: - _Resolver
-
+extension Container: _Resolver {
     // swiftlint:disable:next identifier_name
     public func _resolve<Service, Arguments>(
         name: String?,

///
/// where `A` and `X` are protocols, `B` is a type conforming `A`, and `Y` is a type conforming `X` 
/// and depending on `A`.
public class Container {
    internal var services = [ServiceKey: ServiceEntryProtocol]()
    fileprivate let parent: Container? // Used by HierarchyObjectScope
    fileprivate var resolutionDepth = 0

    }
}

// MARK: - Resolver
extension Container: Resolver {
    /// Retrieves the instance with the specified service type.
