I have just started with puppet and I have an elementary question on using variables in a class. This is my class

```
# == Class: mysql::configure_mysql
class mysql::configure_mysql inherits mysql {

  $mysql_backup = "/var/mysql_backup"

  #Create directories 
  file { 'mysql_backup':
    path   => '($mysql_backup)',
    ensure => 'directory',
  }
}

```

I am getting an error 

```
Error: Failed to apply catalog: Parameter path failed on File[mysql_backup]: File paths must be fully qualified, not '($mysql_backup)'

```

Can someone please help me with how to declare a variable and use it?

I have used this for reference: <https://serverfault.com/questions/41577/how-to-fix-puppet-fully-qualified-parameter-path-error>

Thanks