public fun addSourceVirtualFiles(virtualFiles: Collection<VirtualFile>) {
        sourceVirtualFiles.addAll(virtualFiles)
    }

    override fun build(): KtSourceModule {
        val virtualFiles = collectVirtualFilesByRoots()
        val psiManager = PsiManager.getInstance(kotlinCoreProjectEnvironment.project)
        val psiFiles = virtualFiles.mapNotNull { psiManager.findFile(it) }