$mb->data_backup() returns a full DATA backup of current database

i thought when i do like this

my $backup_db = $mb->data_backup();

my $file = $backup_db;
$file .= ".sql";
[download]

i will be able to have the full backup file and give it extension and save it to my dir

Why did you think that based on what you just pasted from the documentation? Again, Tutorials->Debugging and Optimization->Basic debugging checklist. Take the time to understand the very basics of what you're trying to do, and how to debug when something doesn't work as you imagine.

any solution or example on how i can make this thing to work