         _ package: String,
         at version: Version,
         toolsVersion: ToolsVersion? = nil,
-        with dependencies: OrderedDictionary<String, OrderedDictionary<String, (PackageRequirement, ProductFilter)>> = [:]
+        with dependencies: KeyValuePairs<String, OrderedDictionary<String, (PackageRequirement, ProductFilter)>> = [:]
     ) {
         serve(package, at: .version(version), toolsVersion: toolsVersion, with: dependencies)
     }

        _ package: String,
        at version: BoundVersion,
        toolsVersion: ToolsVersion? = nil,
        with dependencies: OrderedDictionary<String, OrderedDictionary<String, (PackageRequirement, ProductFilter)>> = [:]
    ) {
        let packageReference = reference(for: package)
        let container = self.containers[package] ?? MockContainer(package: packageReference)

            let packageDependencies: [MockContainer.Dependency] = filteredDependencies.map {
                (container: reference(for: $0), requirement: $1.0, products: $1.1)
            }
            container.dependencies[version.description, default: [:]][product, default: []] += packageDependencies
        }
        self.containers[package] = container
    }
