Method empty

test/testlibrary.cpp:96–102

    }

    void empty() const {
        // Reading an empty library file is considered to be OK
        constexpr char xmldata[] = "<?xml version=\"1.0\"?>\n<def/>";
        Library library;
        ASSERT(LibraryHelper::loadxmldata(library, xmldata, sizeof(xmldata)));
        ASSERT(library.functions().empty());
    }

    void function() const {
        constexpr char xmldata[] = "<?xml version=\"1.0\"?>\n"