assert targets.empty
    }

    void assertTargetsAreTools() {
        assertTargetsAre(ProductType.TOOL)
    }

    void assertTargetsAreDynamicLibraries() {
        assertTargetsAre(ProductType.DYNAMIC_LIBRARY)
    }

    void assertTargetsAre(ProductType productType) {
        targets.each { it.assertIs(productType) }
    }

    private <T extends PBXObject> T toPbxObject(String id) {

        }
    }

    public enum ProductType {
        INDEXER("org.gradle.product-type.indexer"),

        STATIC_LIBRARY("com.apple.product-type.library.static"),
        DYNAMIC_LIBRARY("com.apple.product-type.library.dynamic"),
        TOOL("com.apple.product-type.tool"),
        BUNDLE("com.apple.product-type.bundle"),
        FRAMEWORK("com.apple.product-type.framework"),

        if (PBXTarget.ProductType.TOOL.equals(productType)) {
            return FileTypes.MACH_O_EXECUTABLE.identifier;
        } else if (PBXTarget.ProductType.DYNAMIC_LIBRARY.equals(productType)) {
            return FileTypes.MACH_O_DYNAMIC_LIBRARY.identifier;
        } else if (PBXTarget.ProductType.STATIC_LIBRARY.equals(productType)) {
            return FileTypes.ARCHIVE_LIBRARY.identifier;

                            target.setProductType(PBXTarget.ProductType.DYNAMIC_LIBRARY);
                        } else if (swiftBinary instanceof SwiftStaticLibrary) {