Method on_document_end

test/basic_parser.cpp:1686–1686

            bool on_document_begin( std::error_code& ) { return true; }
            bool on_document_end( std::error_code& ) { return true; }
            bool on_object_begin( std::error_code& ) { return true; }
            bool on_object_end( std::size_t, std::error_code& ) { return true; }
            bool on_array_begin( std::error_code& ) { return true; }