const bool axes_have_legend = parent_->legend() != nullptr;

if (axes_have_legend) {

const bool all_objects_have_legend =

parent_->legend()->strings().size() >=

parent_->children().size();

if (all_objects_have_legend) {

parent_->legend()->strings().emplace_back(

"data " + num2str(parent_->children().size() + 1));

}

}

std::vector<std::string>::iterator &titles_end) {

if (!display_name_.empty()) {

// if this object has its own display name

return legend_string(display_name_);

} else {

// by default, take just one title

std::string res;

if (titles_begin != titles_end) {

res += legend_string(*titles_begin);

}

++titles_begin;

return res;

}