 
     final class ModuleResult {
         private let module: Module
-        private lazy var sources: Set<RelativePath> = { Set(self.module.sources.relativePaths) }()
 
         fileprivate init(_ module: Module) {
             self.module = module

            if let root = root {
                XCTAssertEqual(module.sources.root, AbsolutePath(root), file: file, line: line)
            }
            var sources = self.sources

            for path in paths.lazy.map(RelativePath.init) {
                let contains = sources.contains(path)
                XCTAssert(contains, "\(path) not found in module \(module.name)", file: file, line: line)
                if contains {
                    sources.remove(path)
                }
            }

            guard sources.isEmpty else {
                return XCTFail("Unchecked sources in package \(self): \(sources)", file: file, line: line)
            }
        }

        func checkSources(root: String? = nil, paths: String..., file: StaticString = #file, line: UInt = #line) {

        }

        func check(dependencies depsToCheck: [String], file: StaticString = #file, line: UInt = #line) {
            XCTAssertEqual(Set(depsToCheck), Set(module.dependencies.map{$0.name}), "unexpected dependencies in \(module.name)")
        }

        func check(recursiveDependencies: [String], file: StaticString = #file, line: UInt = #line) {
