api,
                { sinceSupplier.apply(it) },
                { apiSpec.apply(it) }
            ).groupedByTarget()

        val sourceFiles =
            ArrayList<File>(extensionsPerTarget.size)

        val packageDir =
            outputDirectory.resolve(packageName.replace('.', File.separatorChar))

        fun sourceFile(name: String) =
            packageDir.resolve(name).also { sourceFiles.add(it) }